Hierarchical energy dissipation-cooperative self-resetting seismic pier column structure

Abstract

The application relates to the technical field of anti-seismic pier columns and discloses a hierarchical energy dissipation-collaborative self-resetting anti-seismic pier column structure which comprises a pier column body, a bent cap arranged at the top of the pier column body, the bent cap being integrally cast with the pier column body, and a column foot steel plate embedded in the bottom surface of the pier column body; a pier column pile cap arranged below the pier column body and corresponding to the pier column body; prestressed tendons, the bottom end of the prestressed tendons being anchored in the pier column pile cap, and the top end of the prestressed tendons penetrating through the pier column body and being anchored at the top of the bent cap; an energy dissipation assembly arranged between the pier column body and the pier column pile cap; and a collaborative resetting assembly fixedly installed between the top surface of the pier column pile cap and the column foot steel plate. The application realizes the organic unification of low residual displacement, high ductility safety reserve, precise controllable damage and rapid post-earthquake function recovery, and significantly improves the seismic toughness and comprehensive benefits in the whole life cycle of the bridge structure.

Description

Technical Field

[0001] This invention relates to the field of seismic pier technology, and in particular to a graded energy dissipation-coordinated self-resetting seismic pier structure. Background Technology

[0002] As the core load-bearing and seismic-resistant components of a bridge structure, the seismic performance of bridge piers directly determines the overall post-earthquake safety and functional recovery capability of the bridge. Current bridge seismic design codes generally adopt a ductile design approach, allowing piers to undergo plastic deformation under seismic loads to dissipate seismic energy and prevent structural collapse. However, the significant plastic deformation of piers under this design mode is irreversible, leading to a substantial decrease in the structural bearing capacity after an earthquake. Furthermore, repair work is complex, time-consuming, and costly; some severely damaged piers may even require demolition and reconstruction, resulting in enormous economic losses and disruption of social transportation.

[0003] To address the problems of excessive residual displacement and difficult post-earthquake repair associated with traditional ductile bridge piers, self-resetting swaying pier technology has gradually become a research and application hotspot. This technology relaxes the constraints between the pier and the foundation and incorporates post-tensioned unbonded prestressed tendons, allowing the pier to repeatedly lift and sway relative to the foundation under seismic loads. After the earthquake, the pier self-resets due to the elastic restoring force of the prestressed tendons, effectively avoiding the irreversible damage problems of traditional piers. Furthermore, existing technologies further enhance the seismic energy dissipation capacity of structures by adding energy-dissipating steel reinforcement and other components, promoting the development of recoverable bridge structures.

[0004] However, the existing self-resetting rocking pier technology system still has many shortcomings that urgently need to be addressed: First, the concrete at the column base is prone to irreversible damage. The contact area between the pier base and the foundation is subjected to repeated concentrated compressive stress and impact loads during the lifting and reset cycle. The direct contact between concrete and concrete lacks a stress diffusion mechanism, which can easily lead to crushing and spalling of the concrete at the contact edge, weakening the structural stiffness and bearing capacity, while increasing the reset resistance. Second, it is difficult to replace energy-dissipating components. Most of the existing energy-dissipating steel bars are fixed to the main concrete, making it difficult to visually inspect the damage state after an earthquake. Replacement requires large-area removal of intact concrete, which can easily cause secondary damage to the main structure. Third, the energy dissipation mechanism is singular. All energy-dissipating components enter the yield state simultaneously, and the activation threshold and capacity of the energy dissipation system cannot be dynamically adapted to the earthquake intensity. Fourth, the reset mechanism is singular, relying entirely on prestressed tendons to provide restoring force. To ensure the reset effect under large deformation, high initial prestress is required, which can easily cause the axial compression ratio of the pier column to exceed the code limit, seriously sacrificing the structural ductility. Furthermore, the prestressed tendons are at risk of stress relaxation, resulting in insufficient reset reliability.

[0005] Therefore, there is an urgent need to develop a new type of seismic-resistant pier structure that takes into account the safety requirements of low axial compression ratio, multi-source coordinated reset and graded energy dissipation. Summary of the Invention

[0006] The purpose of this invention is to provide a graded energy dissipation-cooperative self-resetting seismic pier structure, which aims to solve or improve at least one of the above-mentioned technical problems.

[0007] To achieve the above objectives, the present invention provides the following solution: The present invention provides a graded energy dissipation-cooperative self-resetting seismic pier structure, including... The pier column body has a cap beam at the top, which is integrally cast with the pier column body, and a column base steel plate is pre-embedded on the bottom surface of the pier column body; A pier support platform, which is located below the pier body and is correspondingly arranged to the pier body; The prestressing tendon has its bottom end anchored in the pier column cap, and its top end penetrates the pier column body and is anchored to the top of the cap beam. Energy-consuming components are located between the pier body and the pier cap. A collaborative reset component is fixedly installed between the top surface of the pier cap and the column base steel plate.

[0008] Preferably, the energy-consuming component includes an energy-consuming angle steel. The top of the energy-consuming angle steel is detachably connected to a pre-embedded steel plate on the side of the pier body by bolts. An elongated hole is opened at the bottom of the energy-consuming angle steel. A rod is pre-embedded in the pier foundation. The rod pre-embedded in the pier foundation passes through the elongated hole and is threadedly connected to a connecting sleeve.

[0009] Preferably, the energy-consuming angle steel is L-shaped, and a connecting plate is fixedly connected to the vertical section of the energy-consuming angle steel. An energy-consuming steel rod is fixedly connected to the connecting plate by bolts, and the bottom end of the energy-consuming steel rod is detachably connected to the connecting sleeve.

[0010] Preferably, the collaborative reset assembly includes several disc spring connectors, each disc spring connector including a disc spring sleeve. The bottom end of the disc spring sleeve is fixedly connected to the pier foundation via a pre-embedded screw. A pad is provided inside the disc spring sleeve. Openings are respectively provided on the top of the pad and the top of the disc spring sleeve. A disc spring assembly is installed between the top wall of the pad and the inner top wall of the disc spring sleeve. A central connecting rod is provided inside the disc spring sleeve, passing through the disc spring assembly. Limiting nuts are threaded to both ends of the central connecting rod. A buffer rubber pad and a limiting steel plate are provided between the disc spring assembly and the limiting nuts. The buffer rubber pad and the limiting steel plate are sleeved on the outside of the central connecting rod. The size of the buffer rubber pad and the limiting steel plate is larger than the opening size. The top end of the central connecting rod is fixedly connected to the pier column body.

[0011] Preferably, the prestressing tendon includes several unbonded steel strands, and both ends of the prestressing tendon are anchored to the pier column cap and the top of the cap beam respectively through prestressing anchors. Spiral reinforcements are installed at both ends of the prestressing tendon, and the spiral reinforcements are arranged in contact with the prestressing anchors.

[0012] Preferably, the pier column body is a reinforced concrete component, the bottom of the pier column body is pre-set with a weakened column foot, and the column foot steel plate is located at the bottom of the weakened column foot.

[0013] Preferably, the embedded screw at the bottom of the disc spring sleeve and the embedded rod at the bottom of the energy-consuming angle steel are both L-shaped.

[0014] The present invention discloses the following technical effects: This invention constructs a multi-source reset system that coordinates post-tensioned prestressing tendons and disc spring assemblies. It ensures effective reset capability under large lateral displacement without requiring high initial prestress, fully preserving the structure's ductility and energy dissipation potential. The coordinated reset assembly, acting as an independent backup reset source, effectively compensates for performance degradation caused by stress relaxation during long-term use of prestressing tendons, significantly improving the overall reliability of the reset system. After an earthquake, the pier can achieve near-complete reset with minimal residual displacement.

[0015] This invention employs energy-dissipating components that can dynamically adapt their energy-dissipating capacity according to the intensity of the seismic input. During moderate earthquakes, the energy-dissipating steel bars yield first and dissipate energy. During major earthquakes, the energy-dissipating angle steel is activated with a delay through the gap in the elongated hole, providing a stable second line of defense against energy loss. This completely solves the vulnerability of a single energy-dissipating mechanism to "all or nothing" conditions, and has excellent safety redundancy, effectively resisting the continuous effects of super-fortified earthquakes and aftershocks.

[0016] Meanwhile, the energy-consuming components adopt detachable bolt connections, allowing for visual inspection of damage and quick replacement after an earthquake, without the need to remove the main concrete, thus avoiding secondary structural damage; the column base steel plates achieve uniform diffusion of compressive stress, effectively solving the problem of crushed and spalled concrete at the column base, ensuring that the main load-bearing structure maintains its elasticity, significantly shortening the post-earthquake repair cycle and reducing repair costs. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the earthquake-resistant pier structure of the present invention; Figure 2 This is an exploded view of the earthquake-resistant pier structure of the present invention; Figure 3 This is a schematic diagram of the pier cap and the collaborative reset assembly of the present invention; Figure 4 This is a schematic diagram of the energy-consuming component structure of the present invention; Figure 5 This is a schematic diagram of the cooperation between the prestressed tendons and the cap beam of the present invention; Figure 6 This is a schematic diagram of the prestressed tendon structure of the present invention; Figure 7 This is a three-dimensional schematic diagram of the disc spring connector structure of the present invention; Figure 8 This is a schematic diagram of the split structure of the disc spring connector of the present invention; Figure 9 This diagram illustrates the results of the disc spring connector under compressed, initial, and tensile states. The components include: 1. Cap beam; 2. Pier column body; 3. Pier column cap; 4. Disc spring connector; 5. Prestressed tendon; 6. Energy dissipating angle steel; 7. Energy dissipating steel bar; 8. Prestressed anchor; 9. Central connecting rod; 10. Disc spring assembly; 11. Disc spring sleeve; 12. Buffer rubber pad; 13. Limiting steel plate; 14. Limiting nut. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Reference Figures 1-9 This invention provides a graded energy dissipation-cooperative self-resetting seismic pier structure, including... The pier body 2 has a cap beam 1 on top of it. The cap beam 1 is cast integrally with the pier body 2. The bottom surface of the pier body 2 has a column base steel plate. Pier column base 3, which is located below the pier column body 2 and is set correspondingly to the pier column body 2; Prestressed tendon 5, the bottom end of prestressed tendon 5 is anchored in the pier column cap 3, and the top end of prestressed tendon 5 penetrates the pier column body 2 and is anchored to the top of cap beam 1. Energy-dissipating components are located between the pier body 2 and the pier cap 3. The collaborative reset component is fixedly installed between the top surface of the pier cap 3 and the column base steel plate.

[0022] Further optimization of the design includes an energy-dissipating angle steel 6. The top of the angle steel 6 is detachably connected to a pre-embedded steel plate on the side of the pier body 2 via bolts. An elongated hole is formed at the bottom of the angle steel 6. A rod is pre-embedded within the pier cap 3, passing through the elongated hole and threaded with a connecting sleeve. The energy-dissipating angle steel 6 is an angle steel component made of low-yield-point steel. Its installation features a delayed triggering mechanism. One side of the angle steel 6 is fastened to the pre-embedded steel plate on the side of the pier body 2 via high-strength bolts, while the other side has an elongated hole, which is bolted to the rod embedded in the pier cap 3. The elongated hole provides an initial free travel clearance, allowing the angle steel 6 to begin bearing pressure only after a certain degree of deformation, primarily dissipating energy through deformation.

[0023] Furthermore, during the installation of the energy-dissipating angle steel 6, high-strength pre-embedded bolts are first pre-embedded in the corresponding positions in the pier body 2 and the pier bearing 3. Then, the bolts are inserted into the holes of the energy-dissipating angle steel 6 and tightened to complete the fixation, which facilitates disassembly and replacement after the earthquake.

[0024] The design was further optimized. The energy-dissipating angle steel 6 is L-shaped, with a connecting plate fixedly connected to its vertical section. The connecting plate is then bolted to an energy-dissipating steel rod 7, the bottom of which is detachably connected to a connecting sleeve. The energy-dissipating steel rod 7 is made of low-yield-point steel and has threads at both ends. Its lower end is connected to a pre-embedded member in the pier cap 3 via a connecting sleeve, and its upper end is threaded to a connecting plate extending from the side of the energy-dissipating angle steel 6. The detachable connection is achieved through bolts, ensuring rapid replacement after an earthquake. The energy-dissipating steel rod 7 is a fast-response component, capable of yielding first during an earthquake and dissipating energy through axial tensile and compressive plastic deformation.

[0025] The scheme is further optimized. The collaborative reset component includes several disc spring connectors 4. Each disc spring connector 4 includes a disc spring sleeve 11. The bottom end of the disc spring sleeve 11 is fixedly connected to the pier column base 3 through a pre-embedded screw. A pad is provided inside the disc spring sleeve 11. Openings are respectively opened on the top of the pad and the top of the disc spring sleeve 11. A disc spring assembly 10 is installed between the top wall of the pad and the inner top wall of the disc spring sleeve 11. A central connecting rod 9 is provided inside the disc spring sleeve 11. The central connecting rod 9 passes through the disc spring assembly 10. Limiting nuts 14 are threaded to both ends of the central connecting rod 9. A buffer rubber pad 12 and a limiting steel plate 13 are provided between the disc spring assembly 10 and the limiting nut 14. The buffer rubber pad 12 and the limiting steel plate 13 are sleeved on the outside of the central connecting rod 9. The size of the buffer rubber pad 12 and the limiting steel plate 13 is larger than the opening size. The top end of the central connecting rod 9 is fixedly connected to the pier column body.

[0026] Furthermore, the disc spring assembly 10 is composed of multiple disc springs arranged in pairs or stacked. The disc springs are made of 60Si2MnA spring steel, with a surface hardened and tempered to a hardness of HRC40~47. The combination of the disc spring assemblies is designed according to the required stiffness and stroke; pairing increases stroke, while stacking increases stiffness. The central connecting rod 9 is made of 40Cr alloy steel with a diameter of not less than 20mm. Its surface is heat-treated to a hardness of HB220~250. A connecting flange is welded to the top of the central connecting rod 9, and the connecting flange is fixed to the column base steel plate by high-strength bolts. The connecting flange thickness is not less than 16mm, and the number of bolts is not less than 4. The limit nut 14 is a high-strength hexagonal thick nut with a thread fit accuracy of 6H with the central connecting rod 9. The buffer rubber pad 12 is made of natural rubber with a Shore hardness of 60±5 and a thickness of not less than 10mm. It is used to buffer the impact load between the disc spring assembly 10 and the limit steel plate 13, reducing noise and wear. The limiting steel plate 13 is made of Q355B steel plate with a thickness of not less than 8mm. Its outer diameter is 10~15mm larger than the opening diameter on the top of the disc spring sleeve 11 and the pad, so as to prevent the central connecting rod 9 from coming out of the disc spring sleeve 11.

[0027] Furthermore, the disc spring connector 4 is arranged independently of the prestressing tendon 5 and is fixed to the top of the pier cap 3 by pre-embedded screws, evenly distributed between the top surface of the pier cap 3 and the column base steel plate. The pre-embedded screws are made of Q355B round steel with a diameter of not less than 20mm, and the length of its L-shaped bend is not less than 250mm. It extends into the pier cap 3 by not less than 500mm. The length of the top of the pre-embedded screw extending beyond the top surface of the cap should be adjusted according to the installation height of the disc spring sleeve 11, generally 50~80mm. Before installation, the disc spring connector 4 needs to undergo a pre-compression test. The pre-compression load is 1.2 times the design maximum load, and the holding time is not less than 5 minutes. After unloading, check the residual deformation of the disc spring assembly. The residual deformation should not exceed 2% of the total stroke of the disc spring assembly. Unqualified disc spring assemblies must not be used.

[0028] The scheme has been further optimized. The prestressing tendon 5 includes several unbonded steel strands. Both ends of the prestressing tendon 5 are anchored to the pier cap 3 and the top of the cap beam 1 through prestressing anchors 8, respectively. Spiral reinforcements are installed at both ends of the prestressing tendon 5, and the spiral reinforcements are set in contact with the prestressing anchors 8. The initial tension of the prestressing tendon 5 has been precisely designed to ensure that the axial compression ratio of the structure during the service stage meets the specifications.

[0029] Further optimization of the design involves constructing the pier main body 2 as a reinforced concrete component. A weakened column base is pre-installed at the bottom of the pier main body 2, reducing the cross-section of the column base area to create a plastic control zone. A column base steel plate is located at the bottom of the weakened column base to protect the concrete, transmit pressure, and effectively protect the column base concrete from localized crushing. The pier main body 2 contacts the pier cap 3 through the weakened column base at its bottom, allowing for uplift and swaying during earthquakes.

[0030] Further optimization of the design: the pre-embedded screw at the bottom of the disc spring sleeve 11 and the pre-embedded rod at the bottom of the energy-consuming angle steel 6 are both L-shaped.

[0031] The specific working process of this invention: During an earthquake, the prestressed tendons 5 provide the main stiffness and restoring force, while the energy dissipation components and the co-restoring components do not yet enter a significant working state. As the vibration increases, the pier body 2 begins to rise, and the energy dissipation steel bar 7 first reaches its yield strength, enters a plastic state, and begins to dissipate a large amount of energy. At the same time, the prestressed tendons 5 are stretched and store elastic potential energy. At this time, the energy dissipation angle steel 6 has not yet fully participated in the work because the gap in the elongated hole has not been exhausted, and the co-restoring components begin to be compressed and store energy. As the vibration continues to increase, the displacement of the pier body 2 increases, and the energy dissipation steel bar 7 undergoes plastic deformation. When the displacement exceeds the gap in the elongated hole of the energy dissipation angle steel 6, the energy dissipation angle steel 6 is forcibly activated, providing a larger and more stable second-stage energy dissipation through buckling and yielding. The disc spring assembly 10 is compressed by the central connecting rod 9, storing high-density elastic deformation energy. The buffer rubber pad 12 can effectively buffer the impact, and the co-restoring components are fully compressed, storing peak elastic energy.

[0032] After the earthquake, the seismic input weakens. With the combined effect of the contraction of the prestressed tendons 5 and the release of the stored elastic potential energy by the disc spring assembly 10, it can efficiently overcome various resistances, including the residual force of the yielded energy-dissipating components, and return the pier body 2 to its initial position almost completely, achieving minimal residual deformation.

[0033] If the energy-dissipating steel bar 7 fails unexpectedly, the energy-dissipating angle steel 6 can still provide critical energy dissipation capabilities. If the prestressing tendon 5 has insufficient restoring force, the disc spring assembly 10 can serve as an effective backup restoring source. This ensures the overall reliability of the system.

[0034] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0035] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A graded energy dissipation-cooperative self-resetting seismic pier structure, characterized in that: include The pier body (2) is provided with a cap beam (1) on the top of the pier body (2). The cap beam (1) is integrally cast with the pier body (2). The bottom surface of the pier body (2) is pre-embedded with a column foot steel plate. Pier column base (3), the pier column base (3) is located below the pier column body (2) and is correspondingly arranged to the pier column body (2); The prestressing tendon (5) is anchored at its bottom end to the pier cap (3), and the top end of the prestressing tendon (5) penetrates the pier body (2) and is anchored at the top of the cap beam (1). Energy-consuming components are located between the pier body (2) and the pier cap (3); The collaborative reset component is fixedly installed between the top surface of the pier cap (3) and the column base steel plate.

2. The graded energy dissipation-cooperative self-resetting seismic pier structure according to claim 1, characterized in that: The energy-consuming component includes an energy-consuming angle steel (6). The top of the energy-consuming angle steel (6) is detachably connected to the pre-embedded steel plate on the side of the pier body (2) by bolts. An elongated hole is opened at the bottom of the energy-consuming angle steel (6). A rod is pre-embedded in the pier support (3). The rod pre-embedded in the pier support (3) passes through the elongated hole and is threadedly connected to a connecting sleeve.

3. The graded energy dissipation-cooperative self-resetting seismic pier structure according to claim 2, characterized in that: The energy-consuming angle steel (6) is L-shaped. A connecting plate is fixedly connected to the vertical section of the energy-consuming angle steel (6). An energy-consuming steel rod (7) is fixedly connected to the connecting plate by bolts. The bottom end of the energy-consuming steel rod (7) is detachably connected to the connecting sleeve.

4. The graded energy dissipation-cooperative self-resetting seismic pier structure according to claim 2, characterized in that: The coordinated reset assembly includes several disc spring connectors (4), each disc spring connector (4) including a disc spring sleeve (11). The bottom end of the disc spring sleeve (11) is fixedly connected to the pier support (3) via a pre-embedded screw. A pad is provided inside the disc spring sleeve (11). Openings are respectively provided on the top of the pad and the top of the disc spring sleeve (11). A disc spring assembly (10) is installed between the top wall of the pad and the inner top wall of the disc spring sleeve (11). A central connecting rod (9) is provided inside the disc spring sleeve (11). 9) The disc spring assembly (10) is installed through the center connecting rod (9) and the two ends of the center connecting rod (9) are respectively threaded with limit nuts (14). A buffer rubber pad (12) and a limit steel plate (13) are provided between the disc spring assembly (10) and the limit nut (14). The buffer rubber pad (12) and the limit steel plate (13) are sleeved on the outside of the center connecting rod (9). The size of the buffer rubber pad (12) and the limit steel plate (13) is larger than the opening size. The top of the center connecting rod (9) is fixedly connected to the column body of the pier.

5. The graded energy dissipation-cooperative self-resetting seismic pier structure according to claim 1, characterized in that: The prestressed tendon (5) includes several unbonded steel strands. The two ends of the prestressed tendon (5) are respectively anchored to the top of the pier column (3) and the cap beam (1) through prestressed anchors (8). The two ends of the prestressed tendon (5) are equipped with spiral bars, which are in contact with the prestressed anchors (8).

6. The graded energy dissipation-cooperative self-resetting seismic pier structure according to claim 1, characterized in that: The pier body (2) is a reinforced concrete component. The bottom of the pier body (2) is pre-set with a weakened column foot, and the column foot steel plate is located at the bottom of the weakened column foot.

7. The graded energy dissipation-cooperative self-resetting seismic pier structure according to claim 4, characterized in that: The pre-embedded screw at the bottom of the disc spring sleeve (11) and the pre-embedded rod at the bottom of the energy-consuming angle steel (6) are both L-shaped.

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