A bridge pier in a strong earthquake area and a post-earthquake repair method thereof

Abstract

The present invention provides a bridge pier in a strong earthquake area and a post-earthquake repair method thereof. When the earthquake force is relatively small, the outer tubular ductile section can be deformed to dissipate energy without the need for repair, and the tubular ductile section can heal itself after the earthquake, thereby ensuring that a small earthquake will not damage it. When the earthquake force is relatively large, the first tubular ductile section and the second tubular ductile section with relatively small structural strength are first crushed and destroyed to dissipate energy, so as to facilitate subsequent targeted repair of the area. When a large earthquake occurs, even if the first tubular ductile section and the second tubular ductile section are crushed and destroyed, the first central bearing column and the second central bearing column and the damaged first tubular ductile section and the second tubular ductile section can still support traffic loads such as emergency rescue vehicles. During the repair period, the first central bearing column and the second central bearing column independently bear the deadweight of the upper bridge, without the need for cumbersome temporary reinforcement and support measures, and can economically and reasonably achieve the design goals of not being damaged by a small earthquake, being repairable by a medium earthquake, and not collapsing by a large earthquake.

Description

Technical Field

[0001] The invention relates to the technical field of bridge engineering, in particular to a bridge pier in a strong earthquake area and a post-earthquake repair method thereof. Background Art

[0002] Prefabricated pier technology is an important part of green bridge construction. Due to the limitation of joint technology, prefabricated piers can usually only use partial prefabrication of components, and key connecting components are still cast in place, which limits the subsequent process, fails to effectively shorten the construction period, and makes it difficult to further improve the prefabrication rate of components. On the other hand, the prefabricated pier components are manufactured in the factory, and the construction quality can usually be effectively guaranteed, but the joints between the components must be completed on site, which becomes a key constraint on the reliability of the prefabricated piers. Therefore, in high-severity earthquake zones, prefabricated piers have to be used with caution or even abandoned.

[0003] According to the requirements of the specifications, the pier capacity protection components should remain intact under the action of large earthquakes, and plastic hinges should be formed at the pier top and bottom. Usually, the plastic hinges of prefabricated piers basically coincide with the joint positions, and conventional joint forms are difficult to meet the ductility requirements of the plastic hinges.

[0004] Based on the principle of "no damage in small earthquakes, repairable in medium earthquakes, and no collapse in large earthquakes", the prefabricated and assembled bridge piers in the existing technology are not fully considered in terms of post-earthquake repairability and post-earthquake residual strength. The existing technology generally adopts a large structural redundancy to prevent joint failure. Post-earthquake repairability is the weakness of the existing technology. It is impossible to effectively design the post-earthquake residual strength of the structure and the maintenance of its own stability during the repair period. There are problems of unreliable post-earthquake strength and difficulty in post-earthquake repair. These two aspects are crucial considerations for assembled bridge piers in strong earthquake areas. After the earthquake, a certain strength is retained for emergency rescue, and repairability is the fundamental guarantee to avoid demolition and reconstruction after the earthquake and to repair earthquake-damaged components at a relatively low cost.

[0005] In view of this, it is necessary to propose a bridge pier in a strong earthquake area and a post-earthquake repair method thereof to solve or at least alleviate the above defects. Summary of the invention

[0006] The main purpose of the present invention is to provide a bridge pier in a strong earthquake area and a post-earthquake repair method thereof, so as to solve the technical problems of unreliable post-earthquake strength and difficult post-earthquake repair of bridge piers in the prior art.

[0007] To achieve the above-mentioned purpose, the present invention provides a bridge pier for strong earthquake areas, comprising a prefabricated pile foundation, a prefabricated cap, a prefabricated pier column and a prefabricated cap beam connected in sequence from bottom to top; wherein:

[0008] The bottom of the prefabricated cap beam is upwardly recessed with a pier column top socket hole matching the top of the prefabricated pier column, and the top of the prefabricated cap is downwardly recessed with a pier column bottom socket hole matching the bottom of the prefabricated pier column. The prefabricated pier column includes an upper docking section, an intermediate main section and a lower docking section connected in sequence along the vertical direction, wherein:

[0009] The upper docking section includes a first central bearing column, a first tubular ductile section located in the plastic hinge section, and a first tubular control section for controlling the length of the plastic hinge section, wherein the first tubular ductile section and the first tubular control section are sequentially arranged on the outer peripheral wall of the first central bearing column from top to bottom;

[0010] The outer peripheral wall of the first central bearing column is coated with a first shape memory alloy layer, the upper end of the first central bearing column is inserted into the socket hole on the top of the pier column, and a first tubular casting space is formed between the socket hole on the top of the pier column and the upper end of the first central bearing column, ultra-high performance concrete is cast in the first tubular casting space to form a first tubular structural layer, the lower end of the first central bearing column is embedded in the interior of the middle main body section, the structural strength of the first tubular ductile section is less than the structural strength of the first central bearing column and the first tubular control section, and the structural strength of the first tubular control section is greater than the structural strength of the middle main body section;

[0011] The lower docking section includes a second central bearing column, a second tubular ductile section located in the plastic hinge section, and a second tubular control section for controlling the length of the plastic hinge section, wherein the second tubular ductile section and the second tubular control section are sequentially arranged on the outer peripheral wall of the second central bearing column from bottom to top;

[0012] The outer peripheral wall of the second central bearing column is covered with a second shape memory alloy layer, the lower end of the second central bearing column is inserted into the socket hole at the bottom of the pier column, and a second tubular casting space is formed between the socket hole at the bottom of the pier column and the lower end of the second central bearing column, ultra-high performance concrete is cast in the second tubular casting space to form a second tubular structural layer, the upper end of the second central bearing column is embedded in the interior of the intermediate main body section, the structural strength of the second tubular ductile section is less than the structural strength of the second central bearing column and the second tubular control section, and the structural strength of the second tubular control section is greater than the structural strength of the intermediate main body section.

[0013] Preferably, the longitudinal main reinforcement of the prefabricated pier column comprises a first extending section, a first connecting section, a reinforcement body section, a second connecting section and a second extending section connected in sequence from top to bottom, wherein:

[0014] The steel bar main section is embedded in the middle main section, the first connecting section is embedded in the first tubular control section, the first extension section is connected to the first connecting section through a first steel bar joint embedded in the first tubular control section, the first extension section extends upward from the first connecting section into the first tubular ductile section, the second connecting section is embedded in the second tubular control section, the second extension section is connected to the second connecting section through a second steel bar joint embedded in the second tubular control section, and the second extension section extends downward from the second connecting section into the second tubular ductile section.

[0015] Preferably, a plurality of inverted U-shaped steel bars surrounding the first central bearing column are embedded in the prefabricated cap beam, and each of the inverted U-shaped steel bars includes a first transverse steel bar segment arranged at the top of the first central bearing column and two first side limb segments respectively arranged on both sides of the first central bearing column, wherein each of the first side limb segments extends downward from the first transverse steel bar segment and extends into the first tubular ductile segment and overlaps with the corresponding first extension segment, or each of the first side limb segments extends downward from the first transverse steel bar segment and extends into the first tubular ductile segment and is spot welded to the corresponding first extension segment.

[0016] Preferably, a plurality of positive U-shaped steel bars surrounding the second central bearing column are embedded in the prefabricated foundation, and each of the positive U-shaped steel bars includes a second transverse steel bar segment arranged at the bottom of the second central bearing column and two second side limb segments respectively arranged on both sides of the second central bearing column, wherein each of the second side limb segments extends upward from the second transverse steel bar segment and extends into the second tubular ductile segment and overlaps with the corresponding second extension segment, or each of the second side limb segments extends downward from the second transverse steel bar segment and extends into the second tubular ductile segment and is spot welded to the corresponding second extension segment.

[0017] Preferably, the prefabricated pile foundation is a prestressed concrete pipe pile.

[0018] Preferably, the bottom of the precast cap is upwardly recessed with a pile foundation socket hole matching the precast pile foundation, and the top of the precast cap is also provided with a grouting hole connected to the pile foundation socket hole, the aperture of the grouting hole is smaller than the aperture of the pile foundation socket hole, the top of the precast pile foundation is inserted into the pile foundation socket hole, and a third tubular casting space is formed between the pile foundation socket hole and the precast pile foundation, and a grouting channel connecting the grouting hole and the third tubular casting space is pre-buried at the bottom of the precast cap, and ductile concrete is poured into the interior of the precast pile foundation, the grouting hole, and the third tubular casting space through the grouting hole to form a third tubular structural layer.

[0019] Preferably, the prefabricated pile foundation includes a pile body, a support plate and anchoring steel bars, wherein the pile body is a tubular pile, the support plate is sealingly connected to the inner wall of the pile body, one end of the anchoring steel bar is connected to the top of the support plate, and the other end extends upward and is flush with the top of the pouring hole; wherein ductile concrete is poured through the pouring hole into the space above the top of the support plate to form a core-cast concrete structure.

[0020] Preferably, the grouting hole includes a hole section of equal diameter and a gradual hole section with gradually increasing hole diameter from top to bottom, the top hole diameter of the gradual hole section is equal to the hole diameter of the equal diameter hole section, and the bottom hole diameter of the gradual hole section is equal to the inner diameter of the pile body.

[0021] Preferably, a vertical hole communicating with the first tubular casting space is opened on the top of the prefabricated cap beam.

[0022] The present invention also provides a post-earthquake repair method for bridge piers in strong earthquake areas, which is applied to the above-mentioned bridge piers in strong earthquake areas and comprises the following steps:

[0023] S1, after the post-earthquake rescue work is completed, the bridge traffic is closed, the first tubular ductile section and the second tubular ductile section are evaluated, and it is determined whether the first tubular ductile section meets a first repair condition, and whether the second tubular ductile section meets a second repair condition;

[0024] S21, when the first tubular ductile section meets the first repair condition, the first tubular ductile section is removed, the first central bearing column bears the bridge constant load, the first tubular ductile section is chiseled out symmetrically in the annular direction, and the first shape memory alloy layer is exposed, and the outer surface of the first central bearing column is cleaned and roughened by using a high-pressure water gun;

[0025] S22, evaluating the residual strain of the first extension segment, and when the residual strain of the first extension segment is less than a first preset threshold, straightening and stress relief treatment are performed on the residual strain of the first extension segment for standby use, and when the residual strain of the first extension segment is greater than or equal to the first preset threshold, reinstalling the first extension segment that meets the requirements;

[0026] S23, re-casting the first tubular ductile section and curing it, so that the prefabricated pier is in a full-section stress state in the first tubular ductile section, and traffic is restored;

[0027] and / or S24, when the second tubular ductile section meets the second repair condition, the second tubular ductile section is removed, the second central bearing column bears the bridge constant load, the second tubular ductile section is chiseled out symmetrically in an annular direction, and the second shape memory alloy layer is exposed, and the outer surface of the second central bearing column is cleaned and roughened by a high-pressure water gun;

[0028] S25, evaluating the residual strain of the second extension segment, and when the residual strain of the second extension segment is less than a second preset threshold, straightening and stress relief treatment are performed on the residual strain of the second extension segment for standby use, and when the residual strain of the second extension segment is greater than or equal to the second preset threshold, reinstalling the second extension segment that meets the requirements;

[0029] S26, re-casting the second tubular ductile section and curing it, forming a full-section stress state of the prefabricated pier in the second tubular ductile section, and resuming traffic.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present application provides a bridge pier in a strong earthquake area and a post-earthquake repair method thereof, which provides a full life cycle system solution for prefabricated and assembled bridge piers in strong earthquake areas, and has significant technical and economic advantages. Specifically, the combined application of the central bearing column and the shape memory alloy layer, such as the combined application of the Fe-SMA iron-based shape memory metal expansion mesh and UHPC, forms an ultra-high strength and ultra-tough docking core area. During an earthquake, based on the ultra-strong elastic memory of the Fe-SMA iron-based shape memory metal expansion mesh and good self-resetting performance, it can better form a combined force system with the external ECC ductile concrete.

[0032] When the earthquake force is small, the outer layer of ECC ductile concrete dissipates energy through deformation, and no repair is required. The ECC ductile concrete heals itself after the earthquake, thus ensuring that it will not be damaged by a small earthquake. When the earthquake force is large (such as a moderate earthquake), the first tubular ductile section and the second tubular ductile section with smaller structural strength are first crushed and destroyed to dissipate energy, so as to facilitate subsequent targeted repairs to the area. In the event of a large earthquake, even if the first tubular ductile section and the second tubular ductile section are crushed and damaged, the first central bearing column and the second central bearing column and the damaged first tubular ductile section and the second tubular ductile section can still support traffic loads such as emergency rescue vehicles. During the repair period, the first central bearing column and the second central bearing column independently bear the deadweight of the upper bridge, without the need for cumbersome temporary reinforcement and support measures, and the design goals of no damage in small earthquakes, repairable in moderate earthquakes, and not collapsing in large earthquakes can be achieved economically and reasonably.

[0033] Secondly, ductile concrete grouting is used between the precast pile foundation and the precast cap to provide a high-ductility connection for the bridge pier foundation during an earthquake. During a strong earthquake, the precast pile foundation and the precast cap can achieve a semi-rigid connection similar to a hinged connection, fully releasing the internal bending moment of the foundation and effectively reducing the risk of damage to capacity-protecting components such as the precast pile foundation and the precast cap.

[0034] In addition, the structure of the present application has good durability, no exposed metal structure, and low maintenance; the prefabricated components have no small exposed structures, that is, no embedded steel bars or other easily deformed structures, which is convenient for manufacturing and transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0036] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present application;

[0037] Figure 2 for Figure 1 A is an enlarged schematic diagram;

[0038] Figure 3 for Figure 1 The enlarged schematic diagram of point B in FIG.

[0039] Figure 4 for Figure 1 The enlarged schematic diagram of point C in FIG.

[0040] Figure 5 This is a schematic diagram of the connection between the first connecting steel bar and the second connecting steel bar in the first post-cast joint in one embodiment of the present application.

[0041] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments.

[0042] Description of Figure Numbers:

[0043] 10. Precast pile foundation; 110. Pile body; 120. Support plate; 130. Anchor steel bar; 140. Grouting channel; 150. Grouting core concrete structure; 20. Precast cap; 210. U-shaped steel bar; 211. Second transverse steel bar segment; 212. Second side segment; 220. Grouting hole; 230. Third tubular structure layer; 30. Precast pier column; 311. First central bearing column; 312. First shape memory alloy layer; 313. First tubular ductile segment; 314. First tubular control segment; 315. First tubular structure layer; 331. Second central bearing column; 332. Second shape memory alloy layer; 333. Second Tubular ductile section; 334, second tubular control section; 335, second tubular structural layer; 336, longitudinal main reinforcement; 3361, first extension section; 3362, first connection section; 3363, reinforcement main section; 3364, second connection section; 3365, second extension section; 337, first reinforcement joint; 338, second reinforcement joint; 40, precast cap beam; 410, inverted U-shaped reinforcement; 411, first transverse reinforcement section; 412, first side limb section; 420, vertical hole; 430, second post-cast joint; 50, precast tie beam; 510, first post-cast joint; 520, first connecting reinforcement; 530, second connecting reinforcement. DETAILED DESCRIPTION

[0044] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0047] In addition, the descriptions of "right part", "middle part" and the like in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "right part" and "middle part" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0048] Please refer to the attached Figures 1 to 4 In one embodiment of the present invention, a bridge pier in a strong earthquake area comprises a prefabricated pile foundation 10, a prefabricated cap 20, a prefabricated pier column 30 and a prefabricated cap beam 40 connected in sequence from bottom to top; wherein, the bottom of the prefabricated cap beam 40 is upwardly recessed with a pier column top socket hole (not shown in the figure) matching the top of the prefabricated pier column 30, and the top of the prefabricated cap 20 is downwardly recessed with a pier column bottom socket hole (not shown in the figure) matching the bottom of the prefabricated pier column 30, and the prefabricated pier column 30 comprises an upper docking section (not shown in the figure), an intermediate main section (not shown in the figure) and a lower docking section (not shown in the figure) connected in sequence along the vertical direction, wherein:

[0049] The upper docking section includes a first central bearing column 311, a first tubular ductile section 313 located in the plastic hinge section, and a first tubular control section 314 for controlling the length of the plastic hinge section. The first tubular ductile section 313 and the first tubular control section 314 are sequentially arranged on the outer peripheral wall of the first central bearing column 311 from top to bottom.

[0050] The outer peripheral wall of the first central bearing column 311 is coated with a first shape memory alloy layer 312, the upper end of the first central bearing column 311 is inserted into the socket hole at the top of the pier column, and a first tubular casting space (not shown in the figure) is formed between the socket hole at the top of the pier column and the upper end of the first central bearing column 311, ultra-high performance concrete is cast in the first tubular casting space to form a first tubular structural layer 315, the lower end of the first central bearing column 311 is embedded in the interior of the middle main body section, the structural strength of the first tubular ductile section 313 is less than the structural strength of the first central bearing column 311 and the first tubular control section 314, and the structural strength of the first tubular control section 314 is greater than the structural strength of the middle main body section;

[0051] The lower docking section includes a second central bearing column 331, a second tubular ductile section 333 located in the plastic hinge section, and a second tubular control section 334 for controlling the length of the plastic hinge section. The second tubular ductile section 333 and the second tubular control section 334 are sequentially arranged on the outer peripheral wall of the second central bearing column 331 from bottom to top.

[0052] The outer peripheral wall of the second central bearing column 331 is covered with a second shape memory alloy layer 332, the lower end of the second central bearing column 331 is inserted into the socket hole at the bottom of the pier, and a second tubular casting space (not shown in the figure) is formed between the socket hole at the bottom of the pier and the lower end of the second central bearing column 331, and ultra-high performance concrete is cast in the second tubular casting space to form a second tubular structural layer 335, and the upper end of the second central bearing column 331 is embedded in the interior of the middle main body section, and the structural strength of the second tubular ductile section 333 is less than the structural strength of the second central bearing column 331 and the second tubular control section 334, and the structural strength of the second tubular control section 334 is greater than the structural strength of the middle main body section.

[0053] It is worth noting that the first central bearing column 311 is the core bearing part of the upper docking section, and the second central bearing column 331 is the core bearing part of the lower docking section. The first central bearing column 311 and the second central bearing column 331 are preferably UHPC concrete columns. The compressive strength and tensile strength of UHPC (ultra-high performance concrete) are far superior to ordinary concrete. The use of UHPC concrete columns not only has high compressive strength, but also has good shear and bending resistance, and can maintain the stability of the structure under complex stress conditions, thereby improving the seismic performance; the first tubular ductile section 313 and the second tubular ductile section 333 are the control areas of strong earthquake deformation and damage. In order to adapt to small earthquakes without damage and medium earthquakes, they are preferably ECC ductile concrete, which has high ductility, high strength, high durability and excellent seismic performance;

[0054] The first tubular control section 314 is used to control the length of the first tubular ductile section 313, and the second tubular control section 334 is used to control the length of the second tubular ductile section 333. Preferably, the first tubular control section 314 and the second tubular control section 334 are both made of UHPC concrete, and the middle main section preferably adopts ordinary concrete columns; the structural strength (such as concrete strength) of the first tubular ductile section 313 is less than the structural strength of the first central bearing column 311 and the first tubular control section 314, and the structural strength of the first tubular control section 314 is greater than the structural strength of the middle main section. More preferably, the first tubular control section 314 and the first central bearing column 311 adopt the same structural strength. In this case, when encountering a large earthquake, the first tubular ductile section 313 will be destroyed before the first tubular control section 314 and the first central bearing column 311, thereby achieving the purpose of controllable destruction area.

[0055] The structural strength of the second tubular ductile section 333 is less than the structural strength of the second central bearing column 331 and the second tubular control section 334, and the structural strength of the second tubular control section 334 is greater than the structural strength of the intermediate main section; more preferably, the second tubular control section 334 and the second central bearing column 331 adopt the same structural strength. In this case, when encountering a large earthquake, the second tubular ductile section 333 will be destroyed before the second tubular control section 334 and the second central bearing column 331, thereby achieving the purpose of controllable destruction area.

[0056] The first shape memory alloy layer 312 and the second shape memory alloy layer 332 are preferably Fe-SMA iron-based shape memory metal expanded mesh, which is used in combination with the UHPC concrete column to form an ultra-high strength and ultra-toughness docking core area, laying a solid foundation for prefabricated and assembled bridge piers to adapt to strong earthquake areas.

[0057] This application provides a full life cycle system solution for prefabricated bridge piers in strong earthquake areas, with significant technical and economic advantages. Specifically, the combination of the central bearing column and the shape memory alloy layer, such as the Fe-SMA iron-based shape memory metal expansion mesh and UHPC, forms an ultra-high strength and ultra-tough docking core area. During an earthquake, based on the ultra-strong elastic memory of the Fe-SMA iron-based shape memory metal expansion mesh and good self-reset performance, it can better form a combined force system with the external ECC ductile concrete.

[0058] When the earthquake force is small, the outer layer of ECC ductile concrete is deformed to dissipate energy, and no repair is required. The ECC ductile concrete is self-healed after the earthquake, thereby ensuring that small earthquakes will not damage it. When the earthquake force is large (such as a moderate earthquake), the first tubular ductile section 313 and the second tubular ductile section 333 with smaller structural strength are first crushed and destroyed to dissipate energy, so as to facilitate subsequent targeted repair of the area. When encountering a large earthquake, even if the first tubular ductile section 313 and the second tubular ductile section 333 are crushed and damaged, the first central bearing column 311 and the second central bearing column 331 and the damaged first tubular ductile section 313 and the second tubular ductile section 333 can still support traffic loads such as emergency rescue vehicles. During the repair period, the first central bearing column 311 and the second central bearing column 331 independently bear the deadweight of the upper bridge, without the need for cumbersome temporary reinforcement and support measures, and can economically and reasonably achieve the design goals of not being damaged by small earthquakes, being repairable by moderate earthquakes, and not collapsing by large earthquakes.

[0059] In addition, the structure of the present application has good durability, no exposed metal structure, and low maintenance; the prefabricated components have no small exposed structures, that is, no embedded steel bars or other easily deformed structures, which is convenient for manufacturing and transportation.

[0060] As a preferred embodiment, the longitudinal main reinforcement 336 of the prefabricated pier column 30 includes a first extension section 3361, a first connection section 3362, a steel bar main section 3363, a second connection section 3364 and a second extension section 3365 connected in sequence from top to bottom, wherein the steel bar main section 3363 is embedded in the middle main section, the first connection section 3362 is embedded in the first tubular control section 314, and the first extension section 3361 is embedded in the first tubular control section 314 through the first steel bar joint 337 The first extension section 3361 is connected to the first connecting section 3362, and extends upward from the first connecting section 3362 into the first tubular ductile section 313. The second connecting section 3364 is embedded in the second tubular control section 334. The second extension section 3365 is connected to the second connecting section 3364 through a second steel bar joint 338 embedded in the second tubular control section 334, and the second extension section 3365 extends downward from the second connecting section 3364 into the second tubular ductile section 333.

[0061] Specifically, the main steel bar section 3363 is embedded in the middle main section, and the first connecting section 3362 and the second connecting section 3364 are respectively embedded in the first tubular control section 314 and the second tubular control section 334. The first extending section 3361 is connected to the first connecting section 3362 through the first steel bar joint 337 and extends into the first tubular ductile section 313, and the second extending section 3365 is connected to the second connecting section 3364 through the second steel bar joint 338 and extends into the second tubular ductile section 333. This design enables the main steel bar to play a better energy dissipation role in the first tubular ductile section 313 and the second tubular ductile section 333.

[0062] The first steel bar joint 337 embedded in the first tubular control section 314 and the second steel bar joint 338 embedded in the second tubular control section 334 are key components. In other words, the first tubular control section 314 in this embodiment can not only control the length of the first tubular ductile section 313, but also provide a pre-embedded foundation for the first steel bar joint 337, so as to facilitate the first extension section 3361 to be detachably connected to the first steel bar joint 337, so as to facilitate the replacement of the damaged first extension section 3361. The second tubular control section 334 can not only control the length of the second tubular ductile section 333, but also provide a pre-embedded foundation for the second steel bar joint 338, so as to facilitate the second extension section 3365 to be detachably connected to the second steel bar joint 338, so as to facilitate the replacement of the damaged second extension section 3365.

[0063] The design of the longitudinal main reinforcement 336 of this embodiment enables the bridge pier to better play an energy dissipation role under earthquake action. When an earthquake occurs, the first tubular ductile section 313 and the second tubular ductile section 333 will preferentially undergo plastic deformation, while the longitudinal main reinforcement 336 transmits and dissipates earthquake energy through its continuity and strength, thereby improving the earthquake resistance of the bridge pier.

[0064] Preferably, the first steel bar joint 337 and the second steel bar joint 338 can be steel bar joints with internal threads, and the outer peripheral walls of the first extension section 3361 and the second extension section 3365 can be provided with external threads matching the internal threads of the steel bar joints, thereby realizing a detachable connection between the first extension section 3361 and the first steel bar joint 337, and a detachable connection between the second extension section 3365 and the second steel bar joint 338.

[0065] As a preferred embodiment, a plurality of inverted U-shaped steel bars 410 surrounding the first central bearing column 311 are embedded in the prefabricated cap beam 40, and each of the inverted U-shaped steel bars 410 includes a first transverse steel bar segment 411 arranged on the top of the first central bearing column 311 and two first side limb segments 412 respectively arranged on both sides of the first central bearing column 311, wherein each of the first side limb segments 412 extends downward from the first transverse steel bar segment 411 and extends into the first tubular ductile segment 313 and overlaps with the corresponding first extension segment 3361, or each of the first side limb segments 412 extends downward from the first transverse steel bar segment 411 and extends into the first tubular ductile segment 313 and is connected to the corresponding first extension segment 3361 by spot welding.

[0066] Specifically, Figure 1 As shown, each inverted U-shaped steel bar 410 includes a first transverse steel bar segment 411 and two first side limb segments 412. The first transverse steel bar segment 411 is arranged on the top of the first central bearing column 311 and is pre-buried in the prefabricated cap beam 40 to play a role of connection and support. The two first side limb segments 412 are respectively arranged on both sides of the first central bearing column 311, extending downward from the first transverse steel bar segment 411 and extending into the first tubular ductile segment 313. The first side limb segments 412 extend into the first tubular ductile segment 313. After being inserted into the ductile section 313, it can be overlapped or spot-welded with the corresponding first extension section 3361. The first side limb section 412 and the first extension section 3361 are overlapped or spot-welded as a whole, and the inverted U-shaped steel bar 410 spans the first central bearing column 311. The inverted U-shaped steel bar 410 can play a dual role of connection and shear resistance. The inverted U-shaped steel bar 410 and the longitudinal main reinforcement 336 of the prefabricated pier column 30 do not need to correspond one to one, but only need to be aligned with the axis. The installation tolerance is large and the force is reliable.

[0067] This connection method allows the inverted U-shaped steel bar 410 to be overlapped or spot-welded to the longitudinal main reinforcement 336 of the prefabricated pier 30 in a normal state or during a small earthquake, thereby enhancing the earthquake resistance. During a larger or strong earthquake, the direct overlap or spot welding between the first side limb segment 412 and the first extension segment 3361 fails (i.e., the first side limb segment 412 and the first extension segment 3361 are offset or disconnected), thereby reducing the earthquake resistance of the first tubular ductile segment 313, so that the first tubular ductile segment 313 is destroyed first, thereby realizing a controllable graded destruction design of the structure.

[0068] As another preferred embodiment, a plurality of positive U-shaped steel bars 210 surrounding the second central bearing column 331 are embedded in the prefabricated foundation 20, and each of the positive U-shaped steel bars 210 includes a second transverse steel bar segment 211 arranged at the bottom of the second central bearing column 331 and two second side limb segments 212 respectively arranged on both sides of the second central bearing column 331, wherein each of the second side limb segments 212 extends upward from the second transverse steel bar segment 211 and extends into the second tubular ductile segment 333 and overlaps with the corresponding second extension segment 3365, or each of the second side limb segments 212 extends downward from the second transverse steel bar segment 211 and extends into the second tubular ductile segment 333 and is spot welded to the corresponding second extension segment 3365.

[0069] Specifically, Figure 1 As shown, each positive U-shaped steel bar 210 includes a second transverse steel bar segment 211 and two second side limb segments 212. The second transverse steel bar segment 211 is arranged at the bottom of the second central bearing column 331 and is pre-buried in the prefabricated cap 20 to play a role of connection and support. The two second side limb segments 212 are respectively arranged on both sides of the second central bearing column 331, extending upward from the second transverse steel bar segment 211 and extending into the second tubular ductile segment 333. The second side limb segments 212 extend into the second tubular ductile segment 333. After being inserted into the shaped ductile section 333, it can be overlapped or spot-welded with the corresponding second extension section 3365. The second side limb section 212 and the second extension section 3365 are overlapped or spot-welded as a whole, and the positive U-shaped steel bar 210 spans the second central bearing column 331. The positive U-shaped steel bar 210 can play a dual role of connection and shear resistance. The positive U-shaped steel bar 210 and the longitudinal main reinforcement 336 of the prefabricated pier column 30 do not need to correspond one to one, but only need to be aligned with the axis. The installation tolerance is large and the force is reliable.

[0070] This connection method allows the positive U-shaped steel bar 210 to be overlapped or spot-welded to the longitudinal main reinforcement 336 of the prefabricated pier 30 in a normal state or during a small earthquake, thereby enhancing the earthquake resistance. During a larger or strong earthquake, the direct overlap or spot welding between the second side segment 212 and the second extension segment 3365 fails (i.e., the second side segment 212 and the second extension segment 3365 are offset or disconnected), thereby reducing the earthquake resistance of the second tubular ductile segment 333, so that the second tubular ductile segment 333 is destroyed first, thereby realizing a controllable graded destruction design of the structure.

[0071] Furthermore, the prefabricated pile foundation 10 is a prestressed concrete pipe pile. Specifically, the prestressed concrete pipe pile adopts high-strength concrete and high-strength steel bars, and has high bearing capacity, strong crack resistance, bending resistance and other rigidity properties.

[0072] As a preferred embodiment, the bottom of the precast cap 20 is recessed upwardly with a pile foundation socket hole (not shown in the figure) for matching the precast pile foundation 10, and the top of the precast cap 20 is also provided with a grouting hole 220 connected to the pile foundation socket hole, the aperture of the grouting hole 220 is smaller than the aperture of the pile foundation socket hole, the top of the precast pile foundation 10 is inserted into the pile foundation socket hole, and a third tubular casting space (not shown in the figure) is formed between the pile foundation socket hole and the precast pile foundation 10, and a grouting channel 140 connecting the grouting hole 220 and the third tubular casting space is pre-buried in the bottom of the precast cap 20, and ductile concrete is poured into the interior of the precast pile foundation 10, the grouting hole 220, and the third tubular casting space through the grouting hole 220 to form a third tubular structural layer 230.

[0073] Specifically, the bottom of the precast cap 20 is recessed upwardly with a pile foundation socket hole matching the precast pile foundation 10, ensuring that the precast pile foundation 10 can be accurately and firmly inserted, wherein the top of the precast cap 20 is also provided with a grouting hole 220 connected to the pile foundation socket hole for pouring ductile concrete, and the bottom of the precast cap 20 is pre-buried with a grouting channel 140 connecting the grouting hole 220 and the third tubular casting space, ensuring that concrete can smoothly pass through the grouting hole 220 and the grouting channel 140 to enter and fill the third tubular casting space. As a preferred example, the bottom of the cap is placed on the ground, so there is no need to set a template at the bottom when pouring the third tubular casting space. The grouting connection forms a tight connection between the cap and the pile foundation. This connection method greatly improves the integrity and stability of the structure and enhances the seismic resistance of the structure. It is also worth noting that conventional bridge piers usually use cast-in-place caps to connect with prefabricated pile groups. The on-site cast-in-place formwork of the cap and the excavation of the cap foundation pit are heavy and take a long time to strengthen. This embodiment realizes the connection between the prefabricated cap 20 and the prefabricated pile foundation 10, improves construction efficiency and shortens the construction period.

[0074] Furthermore, the number of the grouting holes 220 is set to be multiple, and a horizontal connecting channel (not shown) can be set between the grouting holes 220 to provide a backup grouting channel when the holes are accidentally blocked during construction.

[0075] As a preferred embodiment, the prefabricated pile foundation 10 includes a pile body 110, a support plate 120 and an anchoring steel bar 130, wherein the pile body 110 is a tubular pile, the support plate 120 is sealed and connected to the inner wall of the pile body 110, one end of the anchoring steel bar 130 is connected to the top of the support plate 120, and the other end extends upward and is flush with the top of the pouring hole 220; wherein, ductile concrete is poured into the space above the top of the support plate 120 through the pouring hole 220 to form a core-cast concrete structure 150.

[0076] Specifically, the prefabricated pile foundation 10 consists of three parts: a pile body 110 (pipe pile), a support plate 120, and an anchoring steel bar 130. The pile body 110 is the main bearing structure and has high strength and durability. The support plate 120 is sealed and connected to the inner wall of the pile body 110 to close and protect the internal space. The anchoring steel bar 130 connects the support plate 120 with the grouting hole 220 to ensure the integrity and stability of the structure. During the construction process, first ensure that the prefabricated pile foundation 10 is accurately inserted into the pile foundation socket of the prefabricated cap 20. Subsequently, ductile concrete is poured into the space above the top of the support plate 120 through the grouting hole 220. This concrete has excellent fluidity and self-compacting properties, and can fully fill and compact the space to form a core-filled concrete structure 150. At the same time, during the pouring process, part of the concrete will enter the third tubular casting space through the grouting channel 140 to further strengthen the connection between the prefabricated pile foundation 10 and the prefabricated cap 20. The formation of the cast-in-place concrete structure 150 significantly improves the bearing capacity of the precast pile foundation 10. The low elastic modulus, high ductility and durability of the ductile concrete make the pile foundation more stable and reliable when bearing external loads. At the same time, the provision of the support plate 120 and the anchor steel bars 130 also enhances the integrity and stability of the structure.

[0077] Furthermore, the grouting hole 220 includes a hole section of equal diameter and a gradual hole section with gradually increasing hole diameter from top to bottom, the top hole diameter of the gradual hole section is equal to the hole diameter of the equal diameter hole section, and the bottom hole diameter of the gradual hole section is equal to the inner diameter of the pile body 110.

[0078] Specifically, the equal-diameter hole section at the upper part of the pouring hole 220 maintains a consistent aperture, which is conducive to the smooth access and positioning of the pouring equipment (such as a concrete pump or a pouring pipe), and reduces the pouring resistance and instability caused by the change in aperture. The design of the gradual hole section allows the aperture to gradually increase from the smaller value of the equal-diameter hole section to the inner diameter of the pile body 110. This transition design helps the concrete to flow smoothly during the pouring process, reduces the eddy current or concrete blockage caused by the sudden change in aperture, thereby improving the pouring efficiency. At the same time, the design of the gradual hole section allows the concrete to gradually adapt to the change in aperture during the pouring process, reduces bubbles and cavities caused by the sudden change in flow rate, and improves the density and uniformity of the concrete.

[0079] Furthermore, a vertical hole 420 connected to the first tubular casting space is provided on the top of the prefabricated cap beam 40. Specifically, during the concrete pouring process, bubbles will be generated inside the concrete, and the existence of the vertical hole 420 provides an effective discharge channel for these bubbles, which helps to reduce the bubble content inside the concrete and improve the density and strength of the concrete. In addition, in a preferred example, the vertical hole 420 can also be used as a grouting hole for pouring the first tubular casting space, achieving dual purposes of one hole.

[0080] Furthermore, those skilled in the art may set the number of precast pile foundations 10, precast caps 20, precast piers 30 and precast cap beams 40 according to actual needs. As a specific example, each pier includes four precast pile foundations 10, two precast caps 20, four precast piers 30 and two precast cap beams 40. The two precast caps 20 are connected by a precast tie beam 50, the precast tie beam 50 and the precast cap 20 are connected by a first post-cast joint 510, and the two precast cap beams 40 are connected by a second post-cast joint 430.

[0081] Furthermore, if Figure 5 As shown, the precast cap beam 40 is precast in multiple sections along the longitudinal direction of the bridge, and the number of precast sections is consistent with the number of precast piers 30. A second post-cast joint 430 is set between each precast cap beam 40, and a first connecting steel bar 520 and a second connecting steel bar 530 are embedded in the second post-cast joint 430. One end of the first connecting steel bar 520 extends outward into the corresponding precast cap beam 40, and the second connecting steel bar 530 extends outward into the corresponding precast cap beam 40. The first connecting steel bar 520 and the second connecting steel bar 530 are overlapped or spot-welded in the second post-cast joint 430. The concrete of the second post-cast joint 430 preferably adopts ECC ductile concrete, and the ECC ductile concrete grade is 1 to 2 grades lower than that of the precast cap beam 40.

[0082] The precast cap beams 40 are connected laterally by the second post-cast joints 430 to ensure that under the action of seismic shear waves, multiple precast piers 30 can be subjected to force in a coordinated manner to share the vertical and horizontal loads of the superstructure. Under the action of reciprocating swinging forces, the weak connection of the steel bars in the second post-cast joints 430 and the ductility of the concrete form hinges between the precast cap beams 40, thereby avoiding the risk of failure of the precast cap beams 40 and foundation and other capacity protection components due to excessive bending moments in the frame formed by the precast cap beams 40, precast piers 30 and precast tie beams 50.

[0083] As a preferred example, the present invention also provides a method for constructing bridge piers in strong earthquake areas, which specifically includes the following steps:

[0084] (1) The prefabricated pile foundation 10 is sunk to the designed elevation by driving or implanting, the cushion layer of the prefabricated cap 20 is leveled, and the support plate 120 and the anchor steel bars 130 are installed;

[0085] (2) hoisting the prefabricated cap 20 and placing it above the prefabricated pile foundation 10, inserting the anchoring steel bars 130 into the grouting holes 220 of the prefabricated cap 20, and then hoisting the prefabricated tie beam 50;

[0086] (3) constructing the core concrete structure 150 of the precast pile foundation 10, the third tubular structure layer 230, and the first post-cast joint 510 between the precast cap 20 and the precast tie beam 50;

[0087] (4) hoisting the prefabricated pier column 30, placing the lower end of the second central bearing column 331 of the prefabricated pier column 30 in the socket hole at the bottom of the pier column, and grouting the second tubular casting space with high-strength grouting material;

[0088] (5) hoisting the prefabricated cap beam 40, inserting the upper end of the first central bearing column 311 of the prefabricated pier 30 into the socket hole on the top of the pier, and grouting the first tubular casting space with high-strength grouting material;

[0089] (6) Install the first extension section 3361 and the second extension section 3365 of the prefabricated pier 30, tie the joint steel bars between the prefabricated cap beams 40, and cast the first tubular ductile section 313, the second tubular ductile section 333 and the second post-cast joint 430 between the prefabricated cap beams 40.

[0090] (7) Construct the top ancillary facilities of the prefabricated cap beam 40 and complete the pier construction.

[0091] The present invention also provides a post-earthquake repair method for bridge piers in strong earthquake areas, which is applied to the above-mentioned bridge piers in strong earthquake areas and comprises the following steps:

[0092] S1, after the post-earthquake rescue work is completed, the bridge traffic is closed, the first tubular ductile section 313 and the second tubular ductile section 333 are evaluated, and it is determined whether the first tubular ductile section 313 meets the first repair condition, and whether the second tubular ductile section 333 meets the second repair condition; specifically, the first repair condition may be that the crack width on the surface of the first tubular ductile section 313 is greater than 0.2 mm or there is a local concrete crush area greater than 2 cm 2 The second repair condition may be that a crack width greater than 0.2 mm appears on the surface of the second tubular ductile section 333 or a local concrete collapse area greater than 2 cm 2 Any one or more of .

[0093] S21, when the first tubular ductile section 313 meets the first repair condition, the first tubular ductile section 313 is removed, the first central bearing column 311 bears the bridge constant load, the first tubular ductile section 313 is symmetrically chiseled out in an annular direction, and the first shape memory alloy layer 312 is exposed, and the outer surface of the first central bearing column 311 is cleaned and roughened by using a high-pressure water gun;

[0094] S22, evaluating the residual strain of the first extension section 3361, and when the residual strain of the first extension section 3361 is less than a first preset threshold, straightening and stress relief treatment are performed on the residual strain of the first extension section 3361 for standby use, and when the residual strain of the first extension section 3361 is greater than or equal to the first preset threshold, reinstalling the first extension section 3361 that meets the requirements;

[0095] S23, re-casting the first tubular ductile section 313 and curing it, so that the prefabricated pier 30 is in a full cross-section stress state in the first tubular ductile section 313, and traffic is restored;

[0096] and / or S24, when the second tubular ductile section 333 meets the second repair condition, the second tubular ductile section 333 is removed, the second central bearing column 331 bears the bridge constant load, the second tubular ductile section 333 is symmetrically chiseled out in an annular direction, and the second shape memory alloy layer 332 is exposed, and the outer surface of the second central bearing column 331 is cleaned and roughened by a high-pressure water gun;

[0097] S25, evaluating the residual strain of the second extension section 3365, when the residual strain of the second extension section 3365 is less than a second preset threshold, straightening and stress relief treatment are performed on the residual strain of the second extension section 3365 for standby use, and when the residual strain of the second extension section 3365 is greater than or equal to the second preset threshold, reinstalling the second extension section 3365 that meets the requirements;

[0098] S26, re-casting the second tubular ductile section 333 and curing it, so that the prefabricated pier 30 is in a full-section stress state in the second tubular ductile section 333, and traffic is restored.

[0099] Specifically, after the post-earthquake rescue work is completed, the bridge traffic is closed and the first tubular ductile section 313 and the second tubular ductile section 333 are evaluated to determine whether they meet their respective repair conditions, such as comprehensive consideration of the degree of damage, residual strain, structural integrity, etc.

[0100] If the tubular ductile section meets the repair conditions, it will be cleared and the central bearing column will temporarily bear the bridge's dead load. Use a high-pressure water gun to clean and roughen the outer surface of the central bearing column to enhance the adhesion between the subsequent casting material and the new surface. Evaluate the residual strain of the extension section, and based on the magnitude of the residual strain, decide whether to straighten, destress and reuse the existing extension section, or replace it with a new extension section that meets the requirements. Re-cast the tubular ductile section to form a full-section stress state of the prefabricated pier 30 in the new tubular ductile section. Perform appropriate maintenance to ensure the strength and durability of the newly cast material. After all repair work is completed, resume traffic use of the bridge.

[0101] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A bridge pier for strong earthquake areas, characterized in that: It includes prefabricated pile foundation, prefabricated cap, prefabricated pier column and prefabricated cap beam connected in sequence from bottom to top; among which: The bottom of the prefabricated cap beam is upwardly recessed with a pier column top socket hole matching the top of the prefabricated pier column, and the top of the prefabricated cap is downwardly recessed with a pier column bottom socket hole matching the bottom of the prefabricated pier column. The prefabricated pier column includes an upper docking section, an intermediate main section and a lower docking section connected in sequence along the vertical direction, wherein: The upper docking section includes a first central bearing column, a first tubular ductile section located in the plastic hinge section, and a first tubular control section for controlling the length of the plastic hinge section, wherein the first tubular ductile section and the first tubular control section are sequentially arranged on the outer peripheral wall of the first central bearing column from top to bottom; The outer peripheral wall of the first central bearing column is coated with a first shape memory alloy layer, the upper end of the first central bearing column is inserted into the socket hole on the top of the pier column, and a first tubular casting space is formed between the socket hole on the top of the pier column and the upper end of the first central bearing column, ultra-high performance concrete is cast in the first tubular casting space to form a first tubular structural layer, the lower end of the first central bearing column is embedded in the interior of the middle main body section, the structural strength of the first tubular ductile section is less than the structural strength of the first central bearing column and the first tubular control section, and the structural strength of the first tubular control section is greater than the structural strength of the middle main body section; The lower docking section includes a second central bearing column, a second tubular ductile section located in the plastic hinge section, and a second tubular control section for controlling the length of the plastic hinge section, wherein the second tubular ductile section and the second tubular control section are sequentially arranged on the outer peripheral wall of the second central bearing column from bottom to top; The outer peripheral wall of the second central bearing column is covered with a second shape memory alloy layer, the lower end of the second central bearing column is inserted into the socket hole at the bottom of the pier column, and a second tubular casting space is formed between the socket hole at the bottom of the pier column and the lower end of the second central bearing column, ultra-high performance concrete is cast in the second tubular casting space to form a second tubular structural layer, the upper end of the second central bearing column is embedded in the interior of the intermediate main body section, the structural strength of the second tubular ductile section is less than the structural strength of the second central bearing column and the second tubular control section, and the structural strength of the second tubular control section is greater than the structural strength of the intermediate main body section.

2. The bridge pier for strong earthquake areas according to claim 1, characterized in that: The longitudinal main reinforcement of the prefabricated pier column includes a first extension section, a first connection section, a reinforcement main section, a second connection section and a second extension section which are connected in sequence from top to bottom, wherein: The steel bar main section is embedded in the middle main section, the first connecting section is embedded in the first tubular control section, the first extension section is connected to the first connecting section through a first steel bar joint embedded in the first tubular control section, the first extension section extends upward from the first connecting section into the first tubular ductile section, the second connecting section is embedded in the second tubular control section, the second extension section is connected to the second connecting section through a second steel bar joint embedded in the second tubular control section, and the second extension section extends downward from the second connecting section into the second tubular ductile section.

3. The bridge pier for strong earthquake areas according to claim 2, characterized in that: A plurality of inverted U-shaped steel bars surrounding the first central bearing column are embedded in the prefabricated cap beam, and each of the inverted U-shaped steel bars includes a first transverse steel bar segment arranged at the top of the first central bearing column and two first side limb segments respectively arranged on both sides of the first central bearing column, wherein each of the first side limb segments extends downward from the first transverse steel bar segment and extends into the first tubular ductile segment and overlaps with the corresponding first extension segment, or each of the first side limb segments extends downward from the first transverse steel bar segment and extends into the first tubular ductile segment and is spot welded to the corresponding first extension segment.

4. The bridge pier for strong earthquake areas according to claim 2, characterized in that: A plurality of positive U-shaped steel bars surrounding the second central bearing column are embedded in the prefabricated foundation, and each of the positive U-shaped steel bars includes a second transverse steel bar segment arranged at the bottom of the second central bearing column and two second side limb segments respectively arranged on both sides of the second central bearing column, wherein each of the second side limb segments extends upward from the second transverse steel bar segment and extends into the second tubular ductile segment and overlaps with the corresponding second extension segment, or each of the second side limb segments extends downward from the second transverse steel bar segment and extends into the second tubular ductile segment and is spot welded to the corresponding second extension segment.

5. The bridge pier for strong earthquake areas according to claim 2, characterized in that: The prefabricated pile foundation is a prestressed concrete pipe pile.

6. The bridge pier for strong earthquake areas according to claim 5, characterized in that: The bottom of the precast cap is upwardly recessed with a pile foundation socket hole matching the precast pile foundation, and the top of the precast cap is also provided with a grouting hole connected to the pile foundation socket hole, the aperture of the grouting hole is smaller than the aperture of the pile foundation socket hole, the top of the precast pile foundation is inserted into the pile foundation socket hole, and a third tubular casting space is formed between the pile foundation socket hole and the precast pile foundation, and a grouting channel connecting the grouting hole and the third tubular casting space is pre-buried at the bottom of the precast cap, and ductile concrete is poured into the interior of the precast pile foundation, the grouting hole, and the third tubular casting space through the grouting hole to form a third tubular structural layer.

7. The bridge pier for strong earthquake areas according to claim 6, characterized in that: The prefabricated pile foundation includes a pile body, a support plate and anchoring steel bars, wherein the pile body is a pipe pile, the support plate is sealingly connected to the inner wall of the pile body, one end of the anchoring steel bar is connected to the top of the support plate, and the other end extends upward and is flush with the top of the pouring hole; wherein ductile concrete is poured through the pouring hole into the space above the top of the support plate to form a core-cast concrete structure.

8. The bridge pier for strong earthquake areas according to claim 7, characterized in that: The grouting hole includes a hole section of equal diameter from top to bottom and a gradual hole section with gradually increasing hole diameter, the top hole diameter of the gradual hole section is equal to the hole diameter of the equal diameter hole section, and the bottom hole diameter of the gradual hole section is equal to the inner diameter of the pile body.

9. The bridge pier for strong earthquake areas according to claim 7, characterized in that: A vertical hole connected to the first tubular casting space is opened on the top of the prefabricated cap beam.

10. A post-earthquake repair method for bridge piers in strong earthquake areas, applied to the bridge piers in strong earthquake areas as claimed in any one of claims 2 to 9, characterized in that: The following steps are involved: S1, after the post-earthquake rescue work is completed, the bridge traffic is closed, the first tubular ductile section and the second tubular ductile section are evaluated, and it is determined whether the first tubular ductile section meets a first repair condition, and whether the second tubular ductile section meets a second repair condition; S21, when the first tubular ductile section meets the first repair condition, the first tubular ductile section is removed, the first central bearing column bears the bridge constant load, the first tubular ductile section is chiseled out symmetrically in the annular direction, and the first shape memory alloy layer is exposed, and the outer surface of the first central bearing column is cleaned and roughened by using a high-pressure water gun; S22, evaluating the residual strain of the first extension segment, and when the residual strain of the first extension segment is less than a first preset threshold, straightening and stress relief treatment are performed on the residual strain of the first extension segment for standby use, and when the residual strain of the first extension segment is greater than or equal to the first preset threshold, reinstalling the first extension segment that meets the requirements; S23, re-casting the first tubular ductile section and curing it, so that the prefabricated pier is in a full-section stress state in the first tubular ductile section, and traffic is restored; and / or S24, when the second tubular ductile section meets the second repair condition, the second tubular ductile section is removed, the second central bearing column bears the bridge constant load, the second tubular ductile section is chiseled out symmetrically in an annular direction, and the second shape memory alloy layer is exposed, and the outer surface of the second central bearing column is cleaned and roughened by a high-pressure water gun; S25, evaluating the residual strain of the second extension segment, and when the residual strain of the second extension segment is less than a second preset threshold, straightening and stress relief treatment are performed on the residual strain of the second extension segment for standby use, and when the residual strain of the second extension segment is greater than or equal to the second preset threshold, reinstalling the second extension segment that meets the requirements; S26, re-casting the second tubular ductile section and curing it, forming a full-section stress state of the prefabricated pier in the second tubular ductile section, and resuming traffic.

Images