Bridge old pier seismic reinforcement structure suitable for high intensity seismic area

Abstract

This invention discloses a seismic reinforcement structure for old bridge piers suitable for high-intensity earthquake zones, comprising an existing abutment, an existing pier, an outer reinforcement zone, a flexible seismic isolation sleeve, and a vertical deformation limiting structure. The outer reinforcement zone is fitted around the existing pier, its bottom end fixed to the existing abutment, and its top end abutting against the bottom of the bridge. The flexible seismic isolation sleeve is sandwiched between the existing pier and the outer reinforcement zone, and is composed of alternating layers of elastic buffer rings and rigid support rings. The vertical deformation limiting structure connects adjacent rigid support rings, used to lock the vertical distance between adjacent rigid support rings when the elastic buffer ring compression rate exceeds the limit due to a strong earthquake. This invention achieves vertical flexible seismic isolation under minor earthquakes through the flexible seismic isolation sleeve, and achieves rigid limiting under strong earthquakes through the vertical deformation limiting structure, forming a two-level adaptive mechanism of "flexible under minor earthquakes and locked under strong earthquakes," preventing excessive compression of the elastic buffer ring, and featuring a simple structure and high reliability.

Description

Technical Field

[0001] This invention relates to the field of bridge technology, specifically to a seismic reinforcement structure for old bridge piers suitable for high-intensity earthquake zones. Background Technology

[0002] In high-intensity earthquake zones, the old bridge piers of existing bridges are mostly designed according to earlier seismic codes, and generally have defects such as insufficient stirrup configuration, insufficient longitudinal steel bar lap length, and low concrete strength, which make it difficult to meet the requirements of current seismic codes. Therefore, seismic reinforcement treatment is required.

[0003] Currently, the main technical solutions for seismic reinforcement of old bridge piers are as follows: The first method is the cross-section enlargement method, which involves pouring reinforced concrete hoops around the existing pier to increase its cross-sectional dimensions. This method provides reliable reinforcement, but it significantly increases the structure's self-weight and stiffness. Increased stiffness leads to a greater seismic response, while reducing the structure's flexibility under normal operating conditions, affecting driving comfort. More importantly, the cross-section enlargement method is a form of "rigid reinforcement," unable to adjust its mechanical properties according to the intensity of seismic motion. Under vertical seismic loading, significant relative deformation can easily occur between the reinforced layer and the existing pier, leading to interface delamination failure.

[0004] The second method is the bonding of fiber-reinforced polymer (FRP) composite materials, which involves bonding carbon fiber or fiberglass cloth to the outer perimeter of the pier to provide circumferential restraint. This method is convenient to construct and does not increase self-weight, but its ductility improvement is limited, and FRP materials are prone to brittle fracture under strong earthquakes. In addition, FRP reinforcement has a limited effect on improving the vertical load transfer path, and under vertical seismic loading, the compressive deformation of the pier is difficult to control effectively.

[0005] The third method is to install seismic isolation layers, which involves placing rubber seismic isolation bearings at the bottom or top of the piers to isolate the structure from the foundation or superstructure. This approach can effectively reduce the horizontal seismic forces transmitted to the piers, but its control over vertical seismic forces is limited. Furthermore, under large vertical loads, the rubber seismic isolation bearings may undergo excessive compression, leading to a decrease in their seismic isolation performance or even failure.

[0006] The common drawback of the aforementioned existing technologies is that traditional reinforcement schemes either only focus on improving horizontal seismic performance, neglecting the impact of vertical seismic forces; or they employ seismic isolation methods using a single material or a single structure, lacking an effective control mechanism for excessive vertical deformation. Specifically: Firstly, under strong vertical seismic action, there will be a large relative vertical displacement between the existing piers and the outer reinforced area, which may cause the elastic isolation layer to be over-compressed and lose its seismic isolation function, or even be crushed and destroyed.

[0007] Secondly, the existing scheme lacks a limiting mechanism that can be automatically triggered based on the vertical compression amount, and cannot provide rigid support in a timely manner when the compression of the isolation layer exceeds the safe range, so as to prevent further deformation of the structure.

[0008] Third, existing solutions often require complex control devices or external energy sources to achieve state switching, making it difficult to guarantee reliability under extreme conditions such as power outages. Summary of the Invention

[0009] To address the shortcomings of existing technologies, the technical problem to be solved by this invention is to provide a seismic reinforcement structure for old bridge piers suitable for high-intensity earthquake zones. This structure can automatically provide rigid restraint when vertical deformation is too large, and is simple in structure and requires no external energy.

[0010] To achieve the above objectives, the present invention provides the following technical solution: a seismic reinforcement structure for old bridge piers suitable for high-intensity earthquake zones, comprising... The system includes existing foundations and existing piers cast on the top surface of the existing foundations, characterized in that it further includes: An outer reinforcement area is fitted around the outer perimeter of the existing pier column. The bottom end of the outer reinforcement area is fixedly connected to the top surface of the existing pier cap, and the top end of the outer reinforcement area abuts against the bottom of the bridge. A flexible seismic isolation reinforcement sleeve is sandwiched between the outer wall of the existing pier and the inner wall of the external reinforcement area. The flexible seismic isolation reinforcement sleeve includes multiple annular elastic buffer rings and multiple annular rigid support rings, with the elastic buffer rings and the rigid support rings alternately stacked in the vertical direction. A vertical deformation limiting structure is connected between two adjacent rigid support rings to lock the vertical distance between the two adjacent rigid support rings when a strong earthquake causes the compression rate of the elastic buffer ring to exceed a predetermined value.

[0011] Furthermore, the elastic buffer ring is provided with through holes spaced apart circumferentially, and multiple vertical deformation limiting structures are provided, with one vertical deformation limiting structure corresponding to each through hole; The vertical deformation limiting structure includes an upper limit block and a lower limit block arranged opposite each other. The upper limit block is fixedly connected to the bottom end of the upper rigid support ring, and the lower limit block is fixedly connected to the top end of the lower rigid support ring. An initial gap is provided between the upper limit block and the lower limit block.

[0012] Furthermore, the vertical deformation limiting structure also includes an elastic support member, which is disposed between the upper limit block and the lower limit block, and the elastic support member is in a free extension state.

[0013] Furthermore, it also includes an anti-rebound mechanism, which includes a first straight rack and a one-way rack. The first straight rack is vertically fixedly connected to the lower rigid support ring, and the one-way rack is vertically fixedly connected to the upper rigid support ring. The first straight rack and the one-way rack can engage in one direction during the process of relatively approaching each other.

[0014] Furthermore, it also includes a lateral deformation limiting structure, which is connected between two adjacent existing piers and is used to lock the lateral distance between the two adjacent existing piers when a strong earthquake causes the lateral displacement between the adjacent existing piers to exceed a predetermined value.

[0015] Furthermore, the lateral deformation limiting structure includes a steel wire and a guide member. The guide member is fixedly connected to the top of the existing pier below. The first end of the steel wire is fixedly connected to the existing pier below. The second end of the steel wire slides through the guide member and is connected to the bottom of the existing pier above. When the lateral distance between two adjacent existing piers reaches a predetermined distance, the steel wire is in a taut and straightened state.

[0016] Furthermore, the lateral deformation limiting structure also includes an automatic reset component connected to the steel wire, which is used to provide a downward reset force to the steel wire.

[0017] Furthermore, the automatic reset component includes a mounting cylinder, a mounting plate, and an elastic connector; the mounting cylinder is fixedly connected to the existing pier below, and the bottom end of the mounting cylinder is closed; the mounting plate is slidably disposed inside the mounting cylinder in the vertical direction; the elastic connector is connected between the bottom wall of the mounting cylinder and the mounting plate; the first end of the steel wire is fixedly connected to the mounting plate.

[0018] Furthermore, the outer reinforcement area is cast in place using ultra-high performance concrete.

[0019] Furthermore, the interior of the outer reinforced area is equipped with a steel mesh.

[0020] The beneficial effects of this invention are: The above-mentioned seismic reinforcement structure for old bridge piers in high-intensity earthquake zones has at least the following advantages: 1. This invention integrates vertical seismic isolation and vertical limiting functions into the same structure by setting a flexible seismic isolation and reinforcement sleeve composed of alternating layers of elastic buffer rings and rigid support rings between the existing pier and the outer reinforcement area, and connecting a vertical deformation limiting structure between two adjacent rigid support rings.

[0021] Under normal operating loads or minor earthquakes, the elastic buffer ring absorbs some of the vibration energy through its own compression deformation, reducing the amplitude of the vertical dynamic load transmitted to the existing piers. The structure maintains a flexible seismic isolation state, ensuring driving comfort. Under strong earthquakes, when the compression rate of the elastic buffer ring exceeds a predetermined value, the vertical deformation limiting structure is automatically triggered, locking the vertical distance between two adjacent rigid support rings to prevent the elastic buffer ring from being over-compressed and damaged. At the same time, the vertical load is directly transmitted to the existing pier through the rigid support rings. This design, which automatically switches the working mode according to the vertical compression, overcomes the technical shortcomings of traditional reinforcement schemes that rely on "single stiffness and cannot address all aspects."

[0022] 2. The vertical deformation limiting structure ensures that, under normal use and minor earthquake conditions, the limiting structure does not participate in load-bearing and does not affect the seismic isolation function of the elastic buffer ring by setting an initial gap between the upper and lower limiting blocks. When the vertical compression exceeds the initial gap, the upper and lower limiting blocks come into contact with each other to form a mechanical stop, preventing further vertical compression. This mechanism provides reliable overload protection for the elastic buffer ring, preventing it from crushing under extreme vertical loads.

[0023] 3. Unlike reinforcement schemes that simply increase stiffness, this invention maintains low stiffness and large deformation capacity under normal use and minor earthquake conditions. The elastic buffer ring is made of high-damping rubber material, which has excellent energy dissipation capacity and elastic recovery performance. The vertical deformation limiting structure is in a standby state in the initial state, does not participate in the load-bearing, does not generate additional stiffness, and has no negative impact on the normal seismic isolation function of the flexible seismic isolation reinforcement sleeve. This characteristic ensures the driving comfort and structural safety of the bridge under normal loads.

[0024] 4. The top of the outer reinforced area of ​​this invention abuts against the bottom of the bridge, and the bottom is fixedly connected to the top surface of the existing abutment, forming a complete vertical force transmission path from the bridge superstructure to the foundation. Under normal use conditions, the vertical load is transmitted through the flexible seismic isolation reinforcement sleeve; under extreme conditions, the vertical load is directly transmitted through the rigid support ring and the vertical deformation limiting structure. This dual-path force transmission design ensures both the seismic isolation effect under normal use and the structural safety under extreme conditions. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the specific embodiments will be briefly described below. In all the drawings, the elements or parts are not necessarily drawn to scale.

[0026] Figure 1 This is a schematic diagram of a seismic reinforcement structure for old bridge piers in high-intensity earthquake zones, provided by an embodiment of the present invention. Figure 2for Figure 1 A schematic diagram at point A in the middle; Figure 3 for Figure 1 The diagram shows the state in which the vertical deformation limiting structure of the old bridge pier seismic reinforcement structure applicable to high-intensity earthquake zones is immediately in the vertical locking stage. Figure 4 for Figure 1 A schematic diagram of the steel wire pulling the mounting plate upwards in the seismic reinforcement structure of old bridge piers in high-intensity earthquake zones, located at point A in the middle. Figure 5 for Figure 1 The diagram shown illustrates how a steel wire pulls an installation plate upwards to its limit position in a seismic reinforcement structure for old bridge piers in high-intensity earthquake zones. Figure label: 100. Existing foundation; 200. Existing pier; 300. External reinforcement zone; 310. Steel mesh; 400. Flexible seismic isolation reinforcement sleeve; 410. Rigid support ring; 420. Elastic buffer ring; 500. Vertical deformation limiting structure; 510. Upper limit block; 520. Lower limit block; 530. Elastic support component; 600. Anti-rebound mechanism; 610. First straight rack; 620. One-way rack; 700. Lateral deformation limiting structure; 710. Steel wire; 720. Guide component; 731. Automatic reset component; 732. Mounting cylinder; 733. Mounting plate; 734. Elastic connector. Detailed Implementation

[0027] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the invention; therefore, the invention is not limited to the specific embodiments disclosed below.

[0028] Please see Figures 1 to 5 This embodiment provides a seismic reinforcement structure for old bridge piers suitable for high-intensity earthquake zones, including an existing abutment 100, an existing pier column 200, an outer reinforcement zone 300, a flexible seismic isolation reinforcement sleeve 400, and a vertical deformation limiting structure 500.

[0029] Specifically, the existing pier cap 100 is a cast-in-place reinforced concrete foundation of the existing bridge. Its top surface is roughened and cleaned to facilitate good bonding with the subsequent cast-in-place structure. Anchoring devices or pre-reserved ducts for subsequent connections can be pre-embedded on the top surface of the existing pier cap 100 according to design requirements. The existing pier 200 is a circular or rectangular cross-section pier of the existing bridge. The surface of the area requiring reinforcement at its bottom perimeter is also cleaned, roughened, and moistened to enhance the interfacial bonding performance between it and the flexible seismic isolation reinforcement sleeve 400 and the outer reinforcement area 300.

[0030] The outer reinforcement zone 300 is fitted around the existing pier 200, with its bottom end fixedly connected to the top surface of the existing abutment 100 and its top end abutting against the bottom of the bridge. The outer reinforcement zone 300 is cast-in-place using ultra-high performance concrete, and its thickness is determined according to seismic design requirements and the cross-sectional dimensions of the existing pier 200. The main function of the outer reinforcement zone 300 is to provide external circumferential restraint for the existing pier 200, improving the pier's load-bearing capacity and ductility, while also providing installation space and physical protection for the flexible seismic isolation reinforcement sleeve 400 and the vertical deformation limiting structure 500. The top end of the outer reinforcement zone 300 abuts against the bottom of the bridge, forming a vertical load transfer path.

[0031] A flexible seismic isolation reinforcement sleeve 400 is sandwiched between the outer wall of the existing pier 200 and the inner wall of the outer reinforcement zone 300. The flexible seismic isolation reinforcement sleeve 400 includes multiple annular elastic buffer rings 420 and multiple annular rigid support rings 410, with the elastic buffer rings 420 and rigid support rings 410 alternately stacked vertically. The elastic buffer rings 420 are made of high-damping rubber material, possessing excellent energy dissipation capacity and aging resistance. The rigid support rings 410 are made of high-strength steel, forming annular steel plate structures. Their inner and outer edges maintain certain gaps with the existing pier 200 and the outer reinforcement zone 300, respectively, ensuring uniform vertical load transfer. The number of layers of elastic buffer rings 420 and rigid support rings 410 is determined according to the height of the outer reinforcement zone 300.

[0032] The vertical deformation limiting structure 500 is connected between two adjacent rigid support rings 410 and is used to lock the vertical distance between the two adjacent rigid support rings 410 when a strong earthquake causes the compression rate of the elastic buffer ring 420 to exceed a predetermined value.

[0033] The working principle of this structure is based on a two-stage mechanical response mechanism of "flexible isolation - vertical locking", which is specifically divided into the following three stages: Phase 1: Normal Use and Minor Earthquake Conditions – Flexible Seismic Isolation Phase Under normal service loads (such as vehicle loads and wind loads) or minor earthquakes, the vertical load borne by the existing pier 200 is jointly borne by the flexible seismic isolation reinforcement sleeve 400 and the outer reinforcement zone 300, and then transferred to the existing abutment 100. The elastic buffer ring 420 absorbs part of the vibration energy through its own compression deformation, reducing the amplitude of the dynamic load transmitted to the existing pier 200. Due to the good elasticity of the elastic buffer ring 420, it can return to its original shape after compression, maintaining the overall height stability of the flexible seismic isolation reinforcement sleeve 400.

[0034] During this stage, the vertical deformation limiting structure 500 is in a standby state, and the vertical distance between the two adjacent rigid support rings 410 remains within the initial range. The vertical deformation limiting structure 500 does not have a locking effect. The entire structure maintains flexible response characteristics during this stage, avoiding unnecessary additional internal forces on the existing pier 200 caused by rigid connections, while ensuring the driving comfort of the bridge superstructure.

[0035] Phase Two: Moderate Earthquake Condition – Elastic Buffer Ring 420 Compression Phase When a moderate earthquake occurs, the vertical acceleration generated by the earthquake increases the vertical load on the existing pier 200, further compressing the elastic buffer ring 420. The compression rate of the elastic buffer ring 420 gradually increases, and the vertical distance between two adjacent rigid support rings 410 gradually decreases.

[0036] During this stage, the initial gap between the upper limit block 510 and the lower limit block 520 in the vertical deformation limiting structure 500 is gradually consumed, and the distance between them gradually decreases, but they have not yet made contact. The vertical deformation limiting structure 500 still does not produce a locking effect, and the elastic buffer ring 420 continues to play its energy dissipation role.

[0037] Phase 3: Strong Earthquake Conditions - Vertical Locking Phase When a strong earthquake occurs and the compression rate of the elastic buffer ring 420 reaches a predetermined value (i.e., the amount of compression deformation of the elastic buffer ring 420 exceeds its design allowable range), the vertical deformation limiting structure 500 is triggered. Specifically, the vertical distance between two adjacent rigid support rings 410 decreases until the upper limit block 510 and the lower limit block 520 come into contact with each other. After contact occurs, the upper limit block 510 and the lower limit block 520 form a mechanical stop, preventing the two adjacent rigid support rings 410 from getting closer to each other, thereby locking the vertical distance between them.

[0038] After locking, the elastic buffer ring 420 no longer bears further compressive load, and the vertical load is directly transferred to the existing foundation 100 through the rigid support ring 410 and the vertical deformation limiting structure 500.

[0039] After the earthquake, as the vertical load decreases, the elastic restoring force of the elastic buffer ring 420 pushes the rigid support ring 410 to gradually separate, and the structure returns to its initial state.

[0040] This approach, through the coordinated operation of the flexible seismic isolation reinforcement sleeve 400 and the vertical deformation limiting structure 500, achieves a two-tiered seismic resistance mechanism of "flexible seismic isolation in minor earthquakes and vertical locking in strong earthquakes." This graded response design concept has the following beneficial effects: First, under normal use and minor earthquake conditions, the elastic buffer ring 420 provides flexible seismic isolation, effectively reducing the seismic force transmitted to the pier and protecting the existing pier 200.

[0041] Second, under strong earthquake conditions, the vertical deformation limiting structure 500 automatically triggers locking to prevent the elastic buffer ring 420 from being damaged by excessive compression, thereby improving the ultimate bearing capacity of the structure.

[0042] Third, the elastic restoring force of the post-earthquake elastic buffer ring 420 can enable the structure to automatically reset, reducing post-earthquake repair costs.

[0043] In this embodiment, the elastic buffer ring 420 has through holes spaced circumferentially. The number of through holes is determined by the diameter of the elastic buffer ring 420, typically 4 to 12, and they are evenly arranged along the circumference. Multiple vertical deformation limiting structures 500 are provided, with one vertical deformation limiting structure 500 corresponding to each through hole. The number of vertical deformation limiting structures 500 is the same as the number of through holes, in a one-to-one correspondence.

[0044] The vertical deformation limiting structure 500 includes an upper limit block 510 and a lower limit block 520 arranged opposite each other. The upper limit block 510 is fixedly connected to the bottom end of the upper rigid support ring 410, and the lower limit block 520 is fixedly connected to the top end of the lower rigid support ring 410. Both the upper limit block 510 and the lower limit block 520 are made of high-strength steel and are cylindrical or prismatic in shape. Their outer diameter matches the inner diameter of the perforation, ensuring that the upper limit block 510 and the lower limit block 520 can slide freely within the perforation.

[0045] An initial gap is provided between the upper limit block 510 and the lower limit block 520. The value of this initial gap ranges from 2 mm to 10 mm, and is determined according to the seismic design requirements and the compressibility of the elastic buffer ring 420. The existence of the initial gap ensures that the upper limit block 510 and the lower limit block 520 do not contact each other under normal use and minor earthquake conditions, and the vertical deformation limiting structure 500 does not produce a locking effect.

[0046] Under normal use and minor earthquake conditions, the compressive deformation of the elastic buffer ring 420 is less than the initial gap, and the upper limit block 510 and the lower limit block 520 remain separated and do not contact each other. The vertical deformation limiting structure 500 does not participate in the stress and does not affect the normal seismic isolation function of the elastic buffer ring 420.

[0047] When a strong earthquake causes the elastic buffer ring 420 to compress and deform to reach the initial gap value, the upper limit block 510 and the lower limit block 520 come into contact with each other. After contact, the upper limit block 510 and the lower limit block 520 form a mechanical stop, preventing the two adjacent rigid support rings 410 from getting closer. Since the upper limit block 510 and the lower limit block 520 are fixed to the upper and lower rigid support rings 410 respectively, they form a rigid connection after contact, locking the vertical distance between the upper and lower rigid support rings 410.

[0048] Because the vertical deformation limiting structure 500 is located within the perforation, and the perforations are evenly distributed along the circumference, the locking force is evenly distributed along the circumference, avoiding localized stress concentration. Simultaneously, the combined effect of multiple vertical deformation limiting structures 500 ensures the reliability of the locking mechanism; even if individual structures fail, the remaining structures can still provide the locking function.

[0049] After the earthquake, the elastic restoring force of the elastic buffer ring 420 pushes the rigid support ring 410 to separate, the contact between the upper limit block 510 and the lower limit block 520 is released, and the structure returns to its initial state.

[0050] Please see Figures 2 to 3 In a preferred embodiment, the vertical deformation limiting structure 500 further includes an elastic support member 530. The elastic support member 530 is disposed between the upper limit block 510 and the lower limit block 520, and the elastic support member 530 is in a freely extended state.

[0051] Specifically, the elastic support 530 is a helical compression spring or a disc spring, which is installed in the cavity between the upper limit block 510 and the lower limit block 520. The upper end of the elastic support 530 abuts or is fixedly connected to the upper limit block 510, and the lower end abuts or is fixedly connected to the lower limit block 520. The elastic support 530 is in a freely elongated state in its initial state, that is, it is not under tension or compression, and is only compressed when the upper limit block 510 and the lower limit block 520 approach each other.

[0052] Under normal use and minor vibration conditions, the elastic buffer ring 420 exhibits minimal compression deformation, and the upper limit block 510 and lower limit block 520 are not yet in contact. Since the elastic support 530 is in a freely elongated state, it does not generate any additional force, thus not affecting the normal compression deformation and vibration isolation function of the elastic buffer ring 420.

[0053] When a strong earthquake causes the upper limit block 510 and the lower limit block 520 to move closer together, the elastic support 530 is compressed, generating an upward elastic restoring force. This elastic restoring force, combined with the elastic restoring force of the elastic buffer ring 420, jointly pushes the rigid support ring 410 to separate, enhancing the structure's post-earthquake recovery capability.

[0054] When the compression deformation of the elastic buffer ring 420 reaches the trigger value, the upper limit block 510 and the lower limit block 520 come into contact with each other to form a mechanical stop.

[0055] In this manner, the elastic support 530 is in a freely elongated state in the initial state, without generating preload, thus avoiding the generation of additional forces under normal use and not affecting the vibration isolation performance of the elastic buffer ring 420. In addition, the presence of the elastic support 530 can also absorb some impact energy and reduce the impact load when the upper limit block 510 and the lower limit block 520 come into contact.

[0056] Please see Figure 3 As a preferred embodiment, the structure further includes an anti-rebound mechanism 600 to prevent the locked structure from unexpectedly rebounding during vibration. Specifically, the anti-rebound mechanism 600 includes a first straight rack 610 and a one-way rack 620. The first straight rack 610 is vertically fixed to the lower rigid support ring 410, and the one-way rack 620 is vertically fixed to the upper rigid support ring 410. The first straight rack 610 and the one-way rack 620 can engage in one direction when they come closer together.

[0057] The tooth surface of the first straight rack 610 and the tooth surface of the one-way rack 620 form a one-way meshing relationship: when the upper limit block 510 moves downward relative to the lower limit block 520 to the predetermined position, the tooth surfaces of the first straight rack 610 and the one-way rack 620 can slide against each other, allowing relative movement. After the earthquake, the elastic restoring force of the elastic buffer ring 420 and the elastic support 530 attempts to push the upper limit block 510 upward, but because the vertical surface of the first straight rack 610 and the vertical surface of the one-way rack 620 abut against each other, a reverse lock is formed, preventing the upper limit block 510 from moving upward.

[0058] This reverse locking mechanism prevents the structure from unexpectedly rebounding under aftershocks or repeated loading, ensuring the continuous reliability of the locked state. When it is necessary to release the lock for maintenance, the one-way rack 620 can be moved outward using a special release tool to disengage it from the first straight rack 610, thus releasing the lock.

[0059] Please see Figures 2 to 5As another preferred embodiment, the structure also includes a lateral deformation limiting structure 700, which is connected between two adjacent existing piers 200 and is used to lock the lateral distance between the two adjacent existing piers 200 when a strong earthquake causes the lateral displacement between the adjacent existing piers 200 to exceed a predetermined value.

[0060] Under normal use and minor earthquake conditions, the lateral displacement between the piers is small, and the lateral deformation limit structure 700 is in a relaxed state, without generating constraint force, and does not affect the normal use of the bridge.

[0061] When a strong earthquake causes the lateral displacement between the piers to increase and exceed a predetermined value, the lateral deformation limiting structure 700 is tightened, reaching a tensioned state. At this time, the lateral deformation limiting structure 700 generates a restraining force, preventing the lateral displacement between the piers from increasing further and preventing the superstructure from falling or colliding due to excessive displacement.

[0062] Specifically, the lateral deformation limiting structure 700 includes a steel wire 710 and a guide member 720. The guide member 720 is fixedly connected to the top of the existing pier 200 located below. The first end of the steel wire 710 is fixedly connected to the existing pier 200 located below, and the second end of the steel wire 710 slides through the guide member 720 and connects to the bottom of the existing pier 200 located above.

[0063] In practical implementation, the guide component 720 is a guide sleeve or pulley with a smooth inner hole, which is fixed to the top of the lower pier column to guide the direction of the steel wire 710. The steel wire 710 is a high-strength steel wire rope or prestressed steel strand, which has high tensile strength and low elongation.

[0064] When the lateral distance between two adjacent existing piers 200 reaches a predetermined distance, the steel wire 710 is in a taut and straightened state. Under normal conditions, the steel wire 710 is in a relaxed state and does not generate restraint force. When the lateral displacement increases and the steel wire 710 is straightened, the steel wire 710 begins to bear tension, preventing further displacement.

[0065] Please see Figures 3 to 5 As a further preferred embodiment, the lateral deformation limiting structure 700 also includes an automatic reset member 730. The automatic reset member 730 is connected to the steel wire 710 and is used to provide a downward reset force to the steel wire 710.

[0066] In this embodiment, the mounting cylinder 731 is fixedly connected to the existing pier 200 located below, and the bottom end of the mounting cylinder 731 is closed; the mounting plate 732 is slidably disposed inside the mounting cylinder 731 in the vertical direction; the elastic connector 733 is connected between the bottom wall of the mounting cylinder 731 and the mounting plate 732; and the first end of the steel wire 710 is fixedly connected to the mounting plate 732.

[0067] During work: Please see Figure 2 In the initial state, the steel wire 710 is in a relaxed state, and its excess length is coiled or stored in the mounting cylinder 731.

[0068] Please see Figure 3 and Figure 4 When a strong earthquake increases the lateral displacement between the piers, the steel wire 710 is straightened. As the lateral displacement continues to increase, the steel wire 710 pulls the mounting plate 732, further stretching the elastic connector 733. The elastic connector 733 is stretched and stores elastic potential energy.

[0069] Please see Figure 5 When the lateral displacement reaches a predetermined value, the steel wire 710 is in a taut and straightened state, and the elastic connector 733 is stretched to its maximum extent. At this time, the mounting plate 732 is at its highest position.

[0070] After the earthquake, the elastic potential energy stored in the elastic connector 733 is released, which drives the mounting plate 732 to move, allowing the steel wire 710 to return to a relaxed state.

[0071] In this embodiment, the outer reinforcement zone 300 is cast-in-place with ultra-high performance concrete. Ultra-high performance concrete is a new type of cement-based composite material with ultra-high strength, high toughness, high durability, and excellent impact resistance. In this embodiment, the ultra-high performance concrete used meets the following technical indicators: compressive strength not less than 120 MPa, flexural strength not less than 20 MPa, ultimate tensile strain not less than 0.3%, elastic modulus not less than 40 GPa, and chloride ion permeability resistance not exceeding coulombs.

[0072] The outer reinforcement zone 300 plays multiple roles in the structure, including: First, providing circumferential constraints by applying circumferential constraint forces to the existing pier 200, thereby improving the pier's bearing capacity and ductility; Second, uniformly distributing loads by spreading the vertical loads and seismic horizontal loads from the pier to the top surface of the pier cap; Third, providing anchoring foundations by providing reliable installation foundations for internal components such as the vertical deformation limiting structure 500; Fourth, protecting internal components by preventing the flexible seismic isolation reinforcement sleeve 400 and other components from being corroded by the external environment.

[0073] Furthermore, internal reinforcement can be added to the 300mm outer reinforcement zone.

[0074] Specifically, the reinforcing mesh 310 is formed by welding or binding longitudinal and transverse reinforcing bars, and has a certain protective layer thickness between it and the surface of the existing pier column 200 and the outer surface of the outer reinforcement zone 300. The lower ends of the longitudinal reinforcing bars of the reinforcing mesh 310 are anchored into the existing pier cap 100, and the upper ends extend below the top surface of the outer reinforcement zone 300. The transverse reinforcing bars of the reinforcing mesh 310 are arranged circumferentially and bound to the longitudinal reinforcing bars.

[0075] The steel mesh 310 plays the following roles in the outer reinforcement zone 300: First, it improves crack resistance and effectively limits the width of cracks; second, it enhances shear bearing capacity and bears part of the shear force; third, it improves ductility, giving the outer reinforcement zone 300 better deformation capacity; fourth, it provides secondary restraint to prevent concrete spalling; and fifth, it improves impact resistance and enhances overall integrity.

[0076] It should be noted that, in specific implementation, corresponding process operation holes should be reserved in the outer reinforcement area 300 to facilitate the installation of relevant tooling inside the outer reinforcement area 300.

[0077] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A bridge old pier seismic reinforcement structure suitable for high intensity seismic areas, comprising an existing pile cap and an existing pier column poured on the top surface of the existing pile cap, characterized in that, Also includes: An outer reinforcement area is fitted around the outer perimeter of the existing pier column. The bottom end of the outer reinforcement area is fixedly connected to the top surface of the existing pier cap, and the top end of the outer reinforcement area abuts against the bottom of the bridge. A flexible seismic isolation reinforcement sleeve is sandwiched between the outer wall of the existing pier and the inner wall of the outer reinforcement area. The flexible seismic isolation reinforcement sleeve includes multiple annular elastic buffer rings and multiple annular rigid support rings, and the elastic buffer rings and the rigid support rings are alternately stacked in the vertical direction. and A vertical deformation limiting structure is connected between two adjacent rigid support rings to lock the vertical distance between the two adjacent rigid support rings when a strong earthquake causes the compression rate of the elastic buffer ring to exceed a predetermined value.

2. The bridge old pier seismic reinforcement structure suitable for high intensity seismic region according to claim 1, characterized in that, The elastic buffer ring is provided with through holes spaced apart circumferentially, and multiple vertical deformation limiting structures are provided, with one vertical deformation limiting structure corresponding to each through hole. The vertical deformation limiting structure includes an upper limit block and a lower limit block arranged opposite each other. The upper limit block is fixedly connected to the bottom end of the upper rigid support ring, and the lower limit block is fixedly connected to the top end of the lower rigid support ring. An initial gap is provided between the upper limit block and the lower limit block.

3. The bridge old pier seismic strengthening structure suitable for high intensity seismic region according to claim 2, characterized in that, The vertical deformation limiting structure also includes an elastic support member, which is disposed between the upper limit block and the lower limit block, and the elastic support member is in a free extension state.

4. The bridge old pier seismic strengthening structure suitable for high intensity seismic region according to claim 2, characterized in that, It also includes an anti-rebound mechanism, which includes a first straight rack and a one-way rack. The first straight rack is vertically fixed to the lower rigid support ring, and the one-way rack is vertically fixed to the upper rigid support ring. The first straight rack and the one-way rack can engage in one direction during the process of relatively approaching each other.

5. The bridge old pier seismic strengthening structure suitable for high intensity seismic regions according to claim 1, characterized in that, It also includes a lateral deformation limiting structure, which is connected between two adjacent existing piers and is used to lock the lateral distance between the two adjacent existing piers when a strong earthquake causes the lateral displacement between the adjacent existing piers to exceed a predetermined value.

6. The bridge old pier seismic strengthening structure suitable for high intensity seismic regions according to claim 5, characterized in that, The lateral deformation limiting structure includes a steel wire and a guide. The guide is fixedly connected to the top of the existing pier below. The first end of the steel wire is fixedly connected to the existing pier below. The second end of the steel wire slides through the guide and connects to the bottom of the existing pier above. When the lateral distance between two adjacent existing piers reaches a predetermined distance, the steel wire is in a taut and straightened state.

7. The bridge old pier seismic strengthening structure suitable for high intensity seismic regions according to claim 6, characterized in that, The lateral deformation limiting structure also includes an automatic reset component connected to the steel wire, which provides a downward reset force to the steel wire.

8. The bridge old pier seismic strengthening structure suitable for high intensity seismic regions according to claim 7, characterized in that, The automatic reset component includes a mounting cylinder, a mounting plate, and an elastic connector; the mounting cylinder is fixedly connected to the existing pier below, and the bottom end of the mounting cylinder is closed; the mounting plate is slidably disposed inside the mounting cylinder in the vertical direction; the elastic connector is connected between the bottom wall of the mounting cylinder and the mounting plate; the first end of the steel wire is fixedly connected to the mounting plate.

9. The seismic reinforcement structure for old bridge piers in high-intensity earthquake zones according to claim 1, characterized in that, The outer reinforcement zone is cast in place with ultra-high performance concrete.

10. The seismic reinforcement structure for old bridge piers in high-intensity earthquake zones according to claim 9, characterized in that, The interior of the outer reinforced area is equipped with steel mesh.

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