Gravity self-resetting heavy load friction sliding support

Abstract

The application provides a gravity self-reset heavy load friction sliding support, and belongs to the technical field of supports of buildings, bridges and the like. The support comprises a first support plate and a second support plate; the two steel support plates are arranged opposite to each other in the vertical direction and jointly form a load bearing and force transmission interface of the support. A set of friction surfaces is directly formed between the first support plate and the second support plate, and the friction surfaces can realize sliding movement in two mutually perpendicular horizontal directions; the friction surfaces as a whole have a symmetrical slope structure, and the slope surface provides a gravity self-resetting guide constraint for the support. When the support slides in two mutually perpendicular horizontal directions and their combinations, the upper structure will be lifted along the slope, and the gravitational potential energy will increase accordingly; after an earthquake, the upper structure will automatically fall back to the initial central position along the slope under the action of gravity, thereby realizing a self-resetting function without additional devices.

Description

Technical Field

[0001] This invention patent belongs to the field of building and bridge bearing technology, specifically relating to a gravity self-resetting heavy-duty friction sliding bearing. Background Technology

[0002] In the field of building and bridge engineering, seismic isolation bearings are core damping components, and their performance directly determines the seismic response and post-earthquake recovery capability of the structure. Currently, the most widely used seismic isolation bearings in engineering are mainly divided into two categories: rubber bearings and friction pendulum bearings. However, both of them have technical bottlenecks that make it difficult to balance efficient energy dissipation and post-earthquake recoverability.

[0003] Among rubber bearings, lead-core rubber bearings and high-damping rubber bearings are widely used due to their excellent hysteretic energy dissipation capabilities. However, earthquake damage surveys and experimental studies have shown that residual deformation of the lead core during repeated plastic deformation and performance degradation of the high-damping rubber material due to strain hysteresis can lead to significant residual displacement of the bearing after an earthquake, and even irreversible damage such as rubber layer tearing and internal component damage. This not only significantly weakens the long-term seismic isolation performance of the bearing, but also significantly increases the cost of post-earthquake structural repair and replacement, making it difficult to meet the engineering requirements for rapid post-earthquake recovery.

[0004] Friction pendulum bearings theoretically possess the technical advantages of extending the structural period, dissipating frictional energy, and self-resetting. However, engineering practice and experimental research have found that, in order to achieve the ideal seismic isolation effect, friction pendulum bearings typically employ a large radius of curvature design. This mechanical geometric characteristic causes the restoring force generated by gravity to decrease significantly when the bearing slider is near its initial geometric center, making it difficult to overcome the frictional force of the friction surface. This, in turn, leads to residual displacement problems after an earthquake, making it impossible to achieve complete self-resetting and weakening the post-earthquake recovery performance of the bearing.

[0005] Therefore, how to overcome the low energy consumption and small vertical bearing capacity of traditional rubber seismic isolation bearings, while solving the technical problems of insufficient self-resetting ability and inability to completely eliminate residual displacement after earthquakes by friction pendulum seismic isolation bearings, and taking into account the energy dissipation and damping performance of the bearings under strong earthquakes and their accurate post-earthquake reset and non-destructive recoverability, balancing seismic isolation efficiency and structural repairability, and adapting to the seismic protection requirements of modern buildings and bridge engineering for high durability and rapid recovery, has become a technical problem that urgently needs to be solved by those skilled in the art.

[0006] It should be noted that the information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0007] This summary is provided to introduce, in a simplified form, some concepts that will be further described in the following detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0008] The purpose of this invention is to provide a gravity self-resetting heavy-duty friction sliding bearing to overcome the low energy consumption and small vertical bearing capacity of traditional rubber seismic isolation bearings, while solving the technical problems of insufficient self-resetting ability and inability to completely eliminate residual displacement after earthquakes in friction pendulum seismic isolation bearings. It also takes into account the energy dissipation and damping performance of the bearing under strong earthquakes and its accurate post-earthquake reset and non-destructive recoverability, balancing seismic isolation efficiency and structural repairability, and adapting to the seismic protection requirements of modern buildings and bridge engineering for high durability and rapid recovery.

[0009] Therefore, the present invention first provides a gravity self-resetting heavy-duty friction sliding support, characterized in that it includes... The first support plate and the second support plate are arranged vertically opposite each other; The first support plate and the second support plate are in direct contact to form a set of friction surfaces, which enable sliding motion in two mutually perpendicular horizontal directions and their combination. The friction surface is composed of a modified polytetrafluoroethylene material and a friction pair material with a low coefficient of friction, forming a friction pair with a low coefficient of friction. The friction surface has a symmetrical slope structure, which provides a guiding constraint for the support to self-reset under gravity. When the first support plate and the second support plate slide along two mutually perpendicular horizontal directions or a combination of directions, the upper structure is lifted along the slope, and the gravitational potential energy increases accordingly. After the earthquake, under the action of gravity, the upper structure will automatically fall back to the initial center position along the slope, realizing the heavy-load self-resetting function without additional devices.

[0010] Preferably, the bidirectional ramp is V-shaped or wavy, and the slope θ of the ramp and the sliding friction coefficient μ of the friction pair satisfy the following: at any sliding position, the component of gravity sliding force is greater than the maximum static friction force; satisfying the formula: μ < n⋅tanθ Where n is a safety factor greater than 1.

[0011] Preferably, the coefficient of sliding friction μ is less than or equal to 0.03, and the slope θ is greater than or equal to 2° and less than or equal to 10°.

[0012] Preferably, the friction pair material with a low coefficient of friction is selected from mirror stainless steel, polymer coating, and chromium plating.

[0013] Preferably, the upper surface or edge of the first support plate is provided with an arc-shaped corner fitting structure to adapt to the corner deformation of the upper structure; the arc-shaped corner fitting structure is an arc transition surface provided on the edge of the first support plate.

[0014] Preferably, both the first support plate and the second support plate are rectangular steel plates, and the bidirectional slopes are symmetrically arranged along the two axes of symmetry of the rectangular steel plates to achieve uniform reset under bidirectional horizontal seismic action.

[0015] Preferably, the edge of the friction surface is provided with a limit stop to limit the maximum sliding displacement of the support and prevent the upper structure from separating from the lower foundation.

[0016] Preferably, the support is further provided with at least one set of tensile connectors for providing additional tensile constraints and for assisting the support in resetting with prestress, wherein the two ends of the tensile connectors are respectively fixed to the first support plate and the second support plate.

[0017] Preferably, the outer sides of the first support plate and the second support plate are provided with highly durable flexible protective covers.

[0018] Preferably, one first support plate and one second support plate form a unidirectional sliding support; or two first support plates and one second support plate form a bidirectional or multidirectional sliding support, wherein the second support plate frictionally slides between the two first support plates.

[0019] This application discloses a gravity-driven self-resetting heavy-load friction sliding bearing. During use, when a horizontal earthquake occurs, the superstructure slides along the bidirectional inclined friction surface of the second support plate via the first support plate. During this sliding process, the superstructure is lifted, increasing its gravitational potential energy. Simultaneously, the relative sliding between the friction surfaces dissipates seismic energy through friction, achieving both seismic isolation and energy dissipation. When the earthquake weakens or disappears, the superstructure automatically returns to its initial center position under gravity, overcoming frictional resistance through slope guidance and gravity restoring force. This achieves a self-resetting function without additional reset devices, effectively controlling residual displacement of the bearing and ensuring the structure can quickly regain its usability after an earthquake.

[0020] The beneficial effects of this invention are as follows: 1. This support adopts a two-way symmetrical slope structure, relying on the self-weight of the superstructure to build a pure gravity self-resetting system, without the need to add additional reset devices such as springs and reset cables, resulting in a simple structure and high reliability.

[0021] 2. This support integrates a limiting block and a tensile connector structure, forming a multi-layered safety protection system. The limiting block effectively restricts the maximum sliding displacement of the support, preventing the upper and lower support plates from separating and causing structural instability and damage under extreme strong earthquakes. The tensile connector provides reliable additional tensile restraint, compensating for the short tensile performance of friction sliding supports, and also assists in support repositioning, further improving the overall safety and repositioning reliability of the support under complex loads and extreme earthquake conditions.

[0022] 3. This support adopts a symmetrical rectangular steel plate structure with bidirectional slopes evenly distributed along the axis of symmetry. This ensures consistent seismic isolation performance, energy dissipation capacity, and recovery performance in both orthogonal horizontal directions, resulting in balanced stress distribution and suitability for the bidirectional seismic resistance requirements of various engineering structures such as buildings and bridges. Furthermore, the structural components can be fixed using conventional processes such as vulcanization, embedding, welding, and bolting, making assembly convenient, processing simple, and suitable for industrialized mass production. It possesses strong engineering practicality and scalability. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the single friction surface support in this invention; Figure 2 yes Figure 1 A schematic diagram of the disassembled structure of the support shown; Figure 3 This is a schematic diagram of the overall structure of the corner-adaptive single-friction surface support in this invention; Figure 4 yes Figure 3 A schematic diagram of the disassembled structure of the support shown; Figure 5 yes Figure 1 Top view of the support shown; Figure 6 This is a schematic diagram of the overall structure of the double friction surface support in this invention; Figure 7 yes Figure 6 A schematic diagram of the disassembled structure of the support shown.

[0024] Wherein: 100, first support plate; 110, modified polytetrafluoroethylene friction surface; 120, arc-shaped corner adaptation structure; 200, second support plate; 210, mirror stainless steel friction surface; 300, tensile connecting piece. Detailed Implementation

[0025] The preferred embodiments described below are merely examples, and other obvious variations will be apparent to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0026] Please see Figure 1 and Figure 2 This embodiment first discloses a gravity self-resetting heavy-duty friction sliding support, including a first support plate 100, a second support plate 200, a friction surface of modified polytetrafluoroethylene material, and a friction surface of a friction pair material with a low coefficient of friction.

[0027] The first support plate 100 and the second support plate 200 are vertically opposite each other and directly contact each other to form a set of friction surfaces. The friction surfaces enable sliding motion in two mutually perpendicular horizontal directions (such as the X and Y planes) and their combination (two-dimensional planar motion). The friction surfaces are composed of modified polytetrafluoroethylene material and friction pair material with low friction coefficient to form a low friction coefficient friction pair. The friction surfaces have a symmetrical slope structure, which provides guidance and constraint for gravity self-resetting of the support. When the first support plate 100 and the second support plate 200 slide along two mutually perpendicular horizontal directions or their combination, the superstructure is lifted along the slope, and the gravitational potential energy increases accordingly. After the earthquake, under the action of gravity, the superstructure will automatically fall back to the initial center position along the slope, realizing the heavy-load self-resetting function without additional devices.

[0028] In a preferred embodiment of this invention, both the first support plate 100 and the second support plate 200 are rectangular steel plates, arranged vertically opposite each other, together forming the load-bearing and force-transmitting interface of the support. The first support plate 100 supports the superstructure, and the second support plate 200 is located on the lower foundation. Specifically, taking a bridge as an example, in this embodiment, the steel support is installed between the superstructure (beam) and the lower foundation (pier / abutment). Further, the upper surface of the first support plate 100 is usually firmly fixed to the bottom surface of the beam by pre-embedded steel plates, high-strength bolts, or welding; similarly, the lower surface of the second support plate 200 is fixed to the top of the lower foundation by pre-embedded anchor bolts, grouting, or welding.

[0029] In a preferred embodiment of this invention, the friction pair material with a low coefficient of friction is selected from mirror stainless steel, polymer coating, and chromium plating. The friction surface is composed of a pair of friction pairs, such as modified polytetrafluoroethylene (PTFE) material paired with mirror stainless steel, modified PTFE material paired with polymer coating, or modified PTFE material paired with chromium plating. The lower surface of the first support plate 100 is preferably configured as a modified PTFE friction surface 110, and the upper surface of the second support plate 200 is preferably fixed as a mirror stainless steel friction surface 210. These two materials constitute a friction pair with a low coefficient of friction. By controlling the dynamic friction coefficient to be less than 0.03, sliding motion in two mutually perpendicular horizontal directions can be achieved.

[0030] The lower surface of the first support plate 100 is fixed with a modified polytetrafluoroethylene friction surface 110 by a vulcanization bonding process, and the upper surface of the second support plate 200 is processed to form a symmetrically arranged bidirectional inclined mirror stainless steel friction surface 210. The two constitute a friction pair with a low coefficient of friction, controlling the dynamic friction coefficient to be less than 0.03, which can realize sliding motion in two mutually perpendicular horizontal directions.

[0031] The bidirectional ramp is V-shaped or wavy. Preferably, the cross-sectional profile of the bidirectional ramp is symmetrically V-shaped, and the slope θ is designed to match the friction coefficient μ of the support contact surface (e.g., the overall friction coefficient of the friction pair formed by the modified polytetrafluoroethylene friction surface 110 and the mirror stainless steel friction surface 210), satisfying μ < ⋅ tanθ. The slope range is preferably 1:30 to 1:10. The slope of the bidirectional ramp is preferably 1:15, the dynamic friction coefficient of the modified polytetrafluoroethylene friction surface 110 is preferably less than 0.03, and the surface roughness Ra of the mirror stainless steel friction surface 210 is less than 0.2 μm, which can ensure low friction and smooth movement during the sliding process.

[0032] Furthermore, the support is also provided with at least one set of tensile connectors 300 to provide additional tensile constraints and assist in the repositioning of the support with prestress. The two ends of the tensile connectors 300 are fixedly connected to the first support plate 100 and the second support plate 200, respectively. The two ends of the tensile connectors 300 are fixedly connected to the upper and lower concave support plates and pass through the sliding support plates, providing additional tensile constraints to prevent the support from detaching under large slip conditions, while also helping to improve the reliability of repositioning. Specifically, the tensile connectors 300 are preferably three symmetrically arranged prestressed steel strands, with both ends fixedly connected to the first support plate 100 and the second support plate 200 through anchors. The initial prestress is a certain proportion of the self-weight of the superstructure, preferably 5% to 10%, used to provide additional tensile constraints and repositioning assistance.

[0033] In some embodiments of this example, limit stops are provided at the edges of the friction surface to limit the maximum sliding displacement of the support and prevent the upper structure from detaching from the lower foundation. (See reference) Figure 6 As shown, a limiting block is further provided at the edge of the friction surface. The limiting block is fixed around the second support plate 200, with a certain gap reserved between it and the edge of the first support plate 100, which can limit the maximum sliding displacement of the support and prevent the upper structure from separating from the lower foundation.

[0034] When a horizontal earthquake occurs, the superstructure slides and rises along the mirror stainless steel friction surface 210 of the bidirectional slope through the first support plate 100, and the gravitational potential energy increases accordingly. At the same time, the relative sliding between the friction surfaces dissipates the seismic energy. After the earthquake, the superstructure automatically falls back to the initial center position along the slope under the combined action of gravity and tensile connector 300, achieving complete self-resetting without additional devices, and the residual displacement is controlled within 1% of the sliding stroke.

[0035] As a preferred embodiment of this example, please refer to Figure 3 and Figure 4 The upper surface or edge of the first support plate 100 is provided with an arc-shaped corner fitting structure to accommodate the corner deformation of the superstructure. Further, the arc-shaped corner fitting structure 120 is an arc-shaped transition surface located at the edge of the first support plate 100. The arc-shaped corner fitting structure 120, located at the upper edge of the first support plate 100, is an arc-shaped transition surface with radius R, which can accommodate the corner deformation of the superstructure and avoid stress concentration at the connection between the support and the superstructure.

[0036] As shown above, a first support plate 100 and a second support plate 200 form a... Figures 1-4 A one-way sliding support. In another preferred embodiment of this application, two first support plates 100 and one second support plate 200 form as follows: Figure 6 and Figure 7 The second support plate 200, acting as a sliding support plate, frictionally slides between the two first support plates 100. This embodiment shares the same basic structure as the aforementioned scheme, including a first support plate 100, a second support plate 200, a modified polytetrafluoroethylene friction surface 110, and a mirror-finished stainless steel friction surface 210. The difference lies in the adoption of a double-sided friction pendulum self-resetting seismic isolation support structure.

[0037] The core structure consists of a central slider-type support plate (first support plate 100) sandwiched between two upper and lower concave support plates (second support plates 200), forming two independent sets of friction surfaces. The overall arrangement is symmetrical, enabling a bidirectional friction pendulum working mode. The support includes two upper and lower concave support plates, i.e., two second support plates 200; and a slider-type support plate located between them, i.e., one first support plate 100. The inner surface of each concave support plate is machined to form a symmetrical slope. The friction surface is a mirror-finished stainless steel friction surface 210, forming one side of the friction pair. The upper and lower surfaces of the slider-type support plate are respectively provided with modified polytetrafluoroethylene friction surfaces 110, which pair with the mirror-finished stainless steel friction surfaces 210 of the upper and lower concave support plates, forming two sets of low-friction friction pairs. Both sets of friction surfaces are symmetrically arranged bidirectional slopes or arc-shaped structures, providing gravity-driven self-resetting guiding constraints for the slider-type support plate.

[0038] Under seismic loading, the slider bearing plate can slide simultaneously on both the upper and lower friction surfaces, forming a double-sided friction pendulum motion mode. The relative sliding of the two friction surfaces dissipates seismic energy, significantly improving the overall energy dissipation capacity. When the slider slides along two mutually perpendicular horizontal directions or their combinations, it rises simultaneously on both the upper and lower arc or slope surfaces, and the gravitational potential energy increases synchronously. After the earthquake, the slider automatically falls back to the initial center position along the upper and lower guide surfaces under the action of gravity. The dual restoring force can effectively overcome friction, avoid the defect of insufficient restoring force at the center position in traditional single friction pendulum bearings, and greatly reduce residual displacement.

[0039] The horizontal displacement of the double-sided friction pendulum is the superposition of the sliding displacements of the upper and lower friction surfaces. Without increasing the overall size of the support, a larger sliding stroke can be achieved, improving seismic isolation efficiency. The symmetrically arranged bidirectional ramps or arc-shaped structures can adapt to horizontal seismic forces in two mutually perpendicular directions, ensuring uniform and stable sliding and recovery performance without directional deviation. Tensile connecting members 300 can be added to the support, with both ends fixedly connected to the upper and lower concave support plates and passing through the sliding block support plate, providing additional tensile constraints to prevent the support from detaching under large sliding conditions, while also helping to improve recovery reliability.

[0040] In this application, the support can be a high-durability, angle-adaptive, gravity-self-resetting, heavy-duty friction sliding support. The outer sides of the first support plate 100 and the second support plate 200 are provided with a high-durability, flexible protective cover. The flexible cover is made of high-durability materials such as silicone rubber, butyl rubber, or polyurethane rubber, which can ensure the long-term stable operation of the support and achieve a long-term maintenance-free effect.

[0041] It should be noted that the present invention has been described in detail above with reference to the accompanying drawings and embodiments. Those skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention shall be defined by the appended claims.

Claims

1. A gravity-driven self-resetting heavy-duty friction sliding support, characterized in that, include: The first support plate and the second support plate are arranged vertically opposite each other; The first support plate and the second support plate are in direct contact to form a set of friction surfaces, which enable sliding motion in two mutually perpendicular horizontal directions and their combination. The friction surface is composed of a modified polytetrafluoroethylene material and a friction pair material with a low coefficient of friction, forming a friction pair with a low coefficient of friction. The friction surface has a symmetrical slope structure, which provides a guiding constraint for the support to self-reset under gravity. When the first support plate and the second support plate slide along two mutually perpendicular horizontal directions or a combination of directions, the upper structure is lifted along the slope, and the gravitational potential energy increases accordingly. After the earthquake, under the action of gravity, the upper structure will automatically fall back to the initial center position along the slope, realizing the heavy-load self-resetting function without additional devices.

2. The gravity self-resetting heavy-duty friction sliding support according to claim 1, characterized in that, The bidirectional ramp is V-shaped or wavy, and the slope θ of the ramp and the sliding friction coefficient μ of the friction pair satisfy the following: at any sliding position, the component of gravity sliding force is greater than the maximum static friction force; satisfying the formula: μ < n⋅tanθ Where n is a safety factor greater than 1.

3. The gravity self-resetting heavy-duty friction sliding support according to claim 2, characterized in that, The sliding friction coefficient μ is less than or equal to 0.03, and the slope θ is preferably in the range of 1:30 to 1:

10.

4. The gravity self-resetting heavy-duty friction sliding support according to claim 1, characterized in that, The friction pair material with a low coefficient of friction is selected from mirror stainless steel, polymer coating, and chromium plating.

5. The gravity self-resetting heavy-load friction sliding support according to claim 1, characterized in that, The upper surface or edge of the first support plate is provided with an arc-shaped corner fitting structure to accommodate the corner deformation of the upper structure; the arc-shaped corner fitting structure is an arc transition surface set on the edge of the first support plate.

6. The gravity self-resetting heavy-duty friction sliding support according to claim 1, characterized in that, Both the first support plate and the second support plate are rectangular steel plates. The bidirectional slopes are symmetrically arranged along the two axes of symmetry of the rectangular steel plates to achieve uniform reset under bidirectional horizontal seismic action.

7. The gravity self-resetting heavy-duty friction sliding support according to claim 1, characterized in that, Limiting blocks are provided at the edges of the friction surface to limit the maximum sliding displacement of the support and prevent the upper structure from separating from the lower foundation.

8. The gravity self-resetting heavy-duty friction sliding support according to claim 1, characterized in that, The support is also provided with at least one set of tensile connectors for providing additional tensile constraints and for prestressing to assist in the repositioning of the support. The two ends of the tensile connectors are respectively fixed to the first support plate and the second support plate.

9. The gravity self-resetting heavy-duty friction sliding support according to claim 1, characterized in that, The first support plate and the second support plate are provided with a highly durable flexible protective cover on their outer sides.

10. The gravity self-resetting heavy-duty friction sliding support according to claim 1, characterized in that, One first support plate and one second support plate form a unidirectional sliding support; or two first support plates and one second support plate form a bidirectional or multidirectional sliding support, wherein the second support plate, as a sliding support plate, frictionally slides between the two first support plates to form two sets of independent friction surfaces.

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