High-intensity earthquake region bridge and construction method and post-earthquake repair method thereof

Abstract

The invention provides a high-intensity earthquake area bridge and a construction method and a post-earthquake repairing method thereof.The bridge comprises a main beam, a cover beam, a pier column and a pile foundation which are sequentially connected from top to bottom, and the pier column comprises an upper connecting section, a middle main body section and a lower connecting section which are sequentially connected in the vertical direction; the upper connecting section comprises a first central bearing column, a first shape memory alloy layer, a first tubular ductile section positioned in the plastic hinge area, and a first annular steel plate and a second annular steel plate which are connected to the peripheral wall of the first central bearing column; the lower connecting section comprises a second central bearing column, a second shape memory alloy layer, a second tubular ductile section located in the plastic hinge area, a third annular steel plate and a fourth annular steel plate, wherein the third annular steel plate and the fourth annular steel plate are connected to the peripheral wall of the second central bearing column. The method can economically and reasonably realize the design goals of no damage in small earthquakes, repairable in medium earthquakes and no falling in large earthquakes.

Description

Technical Field

[0001] The invention relates to the technical field of bridge engineering, in particular to a bridge in a high-intensity earthquake zone and a construction method and a post-earthquake repair method thereof. Background Art

[0002] In high-intensity earthquake areas, earthquake damage is a form of bridge damage that cannot be ignored. Due to the stress characteristics of bridges, earthquakes may usually cause the substructure of the bridge to be damaged before the superstructure, causing the superstructure to lose effective support and even causing the bridge to collapse.

[0003] The seismic reliability of the pier structure is the key control node of the overall seismic performance of the bridge. According to the seismic experience of the bridge industry, the first locations where plastic damage occurs in the pier structure are: the area near the connection between the upper end of the pier column and the cap beam, and the area near the connection between the lower end of the pier column and the foundation, which is called the plastic hinge. The structural reliability and post-earthquake repairability of the plastic hinge area are the key control factors affecting the promotion and application of bridges in high-intensity earthquake zones. The post-earthquake residual bearing capacity of the plastic hinge is the fundamental guarantee for the bridge to survive a major earthquake.

[0004] The design concept of the engineering structure is the principle of "no damage in small earthquakes, repairable in medium earthquakes, and no collapse in large earthquakes". The main work of existing technologies is to prevent damage in small earthquakes, but there is a large gap in the maintainability of bridge piers after earthquakes and the residual strength after earthquakes. Conventional bridge piers usually use larger structural sections to prevent plastic hinge failure, but this will cause the plastic hinge to move upward or damage the protective components, and the maintainability after the earthquake is poor; the residual strength of the structure after the earthquake and the self-stability during the repair process are difficult to evaluate. Or the external energy-absorbing device structure at the upper and lower ends of the bridge pier has the disadvantages of complex installation, exposed metal structure, high maintenance cost, and poor landscape effect. Isolation facilities need to be set up to prevent damage or loss of exposed devices, which is not conducive to the use of space under the bridge.

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

[0006] The main purpose of the present invention is to provide a bridge in a high-intensity earthquake zone and a construction method 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 bridges in the prior art.

[0007] To achieve the above object, the present invention provides a bridge in a high-intensity earthquake zone, comprising a main beam, a cap beam, a pier column and a pile foundation connected in sequence from top to bottom, wherein the pier column comprises an upper connecting section, an intermediate main section and a lower connecting section connected in sequence vertically, wherein:

[0008] The upper connecting section includes a first central bearing column, a first shape memory alloy layer, a first tubular ductile section located in a plastic hinge area, and a first annular steel plate and a second annular steel plate connected to the outer peripheral wall of the first central bearing column, wherein the upper end of the first central bearing column extends into the pier column and is connected to the cap beam, and the lower end of the first central bearing column is arranged in the middle main section; the first tubular ductile section is connected to the outer peripheral wall of the first central bearing column, and the structural strength of the first tubular ductile section is less than the structural strength of the first central bearing column; the first annular steel plate is located at the interface between the first tubular ductile section and the cap beam, and the second annular steel plate is located at the interface between the first tubular ductile section and the middle main section; the first shape memory alloy layer is tubular and is arranged in the first tubular ductile section, and the first shape memory alloy layer, the first tubular ductile section and the first central bearing column are arranged coaxially;

[0009] The lower connecting section includes a second central bearing column, a second shape memory alloy layer, a second tubular ductile section located in the plastic hinge area, and a third annular steel plate and a fourth annular steel plate connected to the outer peripheral wall of the second central bearing column, wherein the lower end of the second central bearing column extends into the pier and is connected to the pile foundation, and the upper end of the second central bearing column is arranged in the middle main section; the second tubular ductile section is connected to the outer peripheral wall of the second central bearing column, and the structural strength of the second tubular ductile section is less than the structural strength of the second central bearing column; the third annular steel plate is located at the interface between the second tubular ductile section and the pile foundation, and the fourth annular steel plate is located at the interface between the second tubular ductile section and the middle main section; the second shape memory alloy layer is tubular and is arranged in the second tubular ductile section, and the second shape memory alloy layer, the second tubular ductile section and the second central bearing column are arranged coaxially.

[0010] Preferably, a plurality of inverted U-shaped steel bars surrounding the first central bearing column are arranged in the cap beam, and each of the inverted U-shaped steel bars includes a transverse steel bar segment arranged on the top of the first central bearing column and two side limb segments respectively connected to both sides of the first central bearing column, wherein each of the side limb segments extends downward from the transverse steel bar segment and is connected to the first annular steel plate.

[0011] Preferably, the top of the longitudinal main reinforcement of the pile foundation is connected to the third annular steel plate, and / or the intermediate main section includes a pier body and pier longitudinal main reinforcements arranged in the pier body, the top of the pier longitudinal main reinforcement is connected to the second annular steel plate, and the bottom of the pier longitudinal main reinforcement is connected to the fourth annular steel plate.

[0012] Preferably, the first annular steel plate, the second annular steel plate, the third annular steel plate, and the fourth annular steel plate are all provided with ventilation holes.

[0013] Preferably, it also includes a plurality of first and second stiffening plates connected to the outer peripheral wall of the first central bearing column, and a plurality of third and fourth stiffening plates connected to the outer peripheral wall of the second central bearing column, the first stiffening plate is arranged in the cap beam and the bottom of the first stiffening plate is connected to the first annular steel plate, the second stiffening plate is arranged in the middle main body section and the top of the second stiffening plate is connected to the second annular steel plate, the third stiffening plate is arranged in the pile foundation and the top of the third stiffening plate is connected to the third annular steel plate, and the fourth stiffening plate is arranged in the middle main body section and the bottom of the fourth stiffening plate is connected to the fourth annular steel plate.

[0014] Preferably, the number of the cap beam, pier and pile foundation along the transverse direction of the bridge is two, wherein when the height of the pier is less than 5m, the two cap beams are connected by a cap beam connecting assembly, the cap beam connecting assembly includes a ductile concrete connecting section, a third shape memory alloy layer coated on the outer surface of the ductile concrete connecting section, and a plurality of reset assemblies arranged at intervals along the longitudinal direction of the bridge, each of the reset assemblies includes two symmetrically arranged Z-shaped shape memory alloy rods, the two Z-shaped shape memory alloy rods cross to form an X-shaped structure, each of the Z-shaped shape memory alloy rods includes a middle working section arranged in the ductile concrete connecting section and two side connecting sections connected to the two ends of the middle section, and each side connecting section is respectively arranged in the corresponding cap beam.

[0015] Preferably, the number of the cap beam, pier and pile foundation along the transverse direction of the bridge is two each. When the height of the pier is 5 to 15 m, the two cap beams are connected by a cap beam connection assembly, and the two pile foundations are rigidly connected by a pile tie beam; wherein the cap beam connection assembly includes a ductile concrete connection section, a third shape memory alloy layer coated on the outer surface of the ductile concrete connection section, and a plurality of reset assemblies arranged at intervals along the longitudinal direction of the bridge, each of the reset assemblies includes two symmetrically arranged Z-shaped shape memory alloy rods, the two Z-shaped shape memory alloy rods cross to form an X-shaped structure, each of the Z-shaped shape memory alloy rods includes a middle working section arranged in the ductile concrete connection section and two side connection sections connected to both ends of the middle section, and each side connection section is respectively arranged in the corresponding cap beam.

[0016] Preferably, the number of the cap beam, pier column and pile foundation along the transverse direction of the bridge is two. When the height of the pier column is greater than 15m, the two cap beams are connected by a cap beam connection assembly, the two pile foundations are rigidly connected by a pile tie beam, and the two pier columns are connected by a column tie beam; wherein,

[0017] The cap beam connection assembly includes a ductile concrete connection section, a third shape memory alloy layer coated on the outer surface of the ductile concrete connection section, and a plurality of reset assemblies arranged at intervals along the longitudinal bridge direction, each of the reset assemblies includes two symmetrically arranged Z-shaped shape memory alloy rods, the two Z-shaped shape memory alloy rods cross to form an X-shaped structure, each of the Z-shaped shape memory alloy rods includes a middle working section arranged in the ductile concrete connection section and two side connection sections connected to the two ends of the middle section, and each side connection section is respectively arranged in the corresponding cap beam.

[0018] The present invention also provides a construction method for a bridge in a high-intensity earthquake zone, which is applied to the above-mentioned bridge in a high-intensity earthquake zone and comprises the following steps:

[0019] S1, drilling / punching holes for pile foundation, making and hoisting pile foundation steel cage in the factory, pouring pile foundation concrete, removing scum concrete and over-cast concrete above the pile top, and then pouring pile tie beam;

[0020] S2, tie up the pier column reinforcement cage, hoist the column tie beam, and pour the pier column concrete;

[0021] S3, tying the cap beam reinforcement mesh, fixing the reset assembly, and pouring the cap beam ordinary concrete;

[0022] S4, installing the first shape memory alloy layer, the second shape memory alloy layer, and the third shape memory alloy layer, and pouring the first tubular ductile section, the second tubular ductile section, and the ductile concrete connecting section in sequence from bottom to top to complete the pier construction;

[0023] S5, construct the bridge superstructure and bridge deck system, complete the bridge construction, and open it to traffic.

[0024] The present invention also provides a post-earthquake repair method for a bridge in a high-intensity earthquake zone, which is applied to the above-mentioned bridge in a high-intensity earthquake zone and comprises the following steps:

[0025] 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 the first repair condition, whether the second tubular ductile section meets the second repair condition, and whether the ductile concrete connecting section meets the third repair condition;

[0026] When the first tubular ductile section meets the first repair condition, the damaged portion of the first tubular ductile section is chiseled out, and the interface is cleaned and roughened with a high-pressure water gun; the residual deformation of the first shape memory alloy layer is then checked, and when the residual deformation of the first shape memory alloy layer mesh exceeds the first preset threshold or is damaged, the first shape memory alloy layer mesh is removed and the remaining first tubular ductile section is chiseled out, and the first shape memory alloy layer mesh that meets the quality requirements is replaced, and the first tubular ductile section is recast and cured to form a full-section stress state of the pier column joint;

[0027] When the second tubular ductile section meets the second repair condition, the damaged portion of the second tubular ductile section is chiseled out, and the interface is cleaned and roughened with a high-pressure water gun; the residual deformation of the second shape memory alloy layer is checked again, and when the residual deformation of the second shape memory alloy layer mesh exceeds the second preset threshold or is damaged, the second shape memory alloy layer mesh is removed and the remaining second tubular ductile section is chiseled out, and the second shape memory alloy layer mesh that meets the quality requirements is replaced, and the second tubular ductile section is recast and cured to form a full-section stress state of the pier column joint;

[0028] When the ductile concrete connection section meets the third repair condition, the third shape memory alloy layer is removed for standby, the ductile concrete connection section is removed, and the reset assembly is protected, the third shape memory alloy layer is reinstalled, and the ductile concrete connection section is re-cast and cured to form the overall stress state of the bridge pier cap beam;

[0029] Repair other ancillary structures of the bridge and resume traffic operation.

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

[0031] The present application provides a bridge for high-intensity earthquake zones and a construction method and a post-earthquake repair method thereof, providing a system solution for the entire life cycle of bridges in high-intensity earthquake zones. Bridges can be easily repaired and reused after an earthquake, and the force system remains unchanged before and after the repair, providing the possibility for secondary repair, with significant technical and economic advantages.

[0032] Specifically, when the earthquake force is relatively small, the tubular ductile sections (such as ECC ductile concrete) in the plastic hinge areas at the upper and lower ends of the piers, the central bearing column (such as a steel cylinder or steel section), and the shape memory alloy layer (such as a Fe-SMA iron-based shape memory extended mesh) cooperate in deformation to consume earthquake energy, thereby ensuring that small earthquakes will not cause damage; when the earthquake force is relatively large (such as a moderate earthquake), the first tubular ductile section and the second tubular ductile section with relatively small structural strength are first crushed and destroyed to consume 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 destroyed, they can still be repaired by the first tubular ductile section. The first and second central bearing columns and the damaged first and second tubular ductile sections support traffic loads such as emergency rescue vehicles. During the repair period, the first and second central bearing columns independently bear the deadweight of the upper bridge, that is, it has good self-stability after the earthquake. After the outer ductile concrete is removed, no additional structural support measures are required, which avoids the need to set up complex hoop structures and support systems for conventional structural repairs. The repair construction is convenient, saving construction time and cost, and can economically and reasonably achieve the design goals of not being damaged by small earthquakes, being repairable by medium earthquakes, and not collapsing by large earthquakes;

[0033] This application connects the cap beam and column tie beam through X-shaped Fe-SMA rods, and sets Fe-SMA expansion nets on the surface of the connection section to ensure self-reset in small and medium earthquakes. In large earthquakes, the X-shaped Fe-SMA rods are deformed to actively weaken the cap beam connection (transmit shear but not bending), and the ductile concrete dissipates energy. With the central bearing column + ductile concrete structure in the plastic hinge area at the upper and lower ends of the pier column, a transverse seismic energy dissipation frame system is formed.

[0034] In addition, this application does not require the installation of external auxiliary devices, has low anti-corrosion requirements, and requires less daily maintenance, which is basically consistent with the maintenance of reinforced concrete structures. No additional isolation measures are required, and the components of each part of the structure can withstand a certain external force, without obvious weak links, and the space under the bridge can be fully developed and utilized on a daily basis. 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 A cross-sectional view of a second stiffening plate in one embodiment of the present application;

[0041] Figure 6 This is a schematic diagram of the overall structure of another embodiment of the present application;

[0042] Figure 7 This is a schematic diagram of the overall structure of another embodiment of the present application;

[0043] Figure 8 It is a schematic elevation diagram of the connection between the column tie beam and the pier column in one embodiment of the present application;

[0044] Fig. 9 It is a schematic plan view of the connection between the column tie beam and the pier column in one embodiment of the present application;

[0045] Fig.10 This is a schematic diagram of the structure before earthquake damage in one embodiment of the present application;

[0046] Fig.11 It is a schematic diagram of the structure after the tubular ductile section is removed in one embodiment of the present application;

[0047] Fig.12 This is a schematic diagram of the structure after the shape memory alloy layer is replaced in one embodiment of the present application;

[0048] Fig.13 It is a schematic diagram of the structure after re-casting of the tubular ductile section in one embodiment of the present application.

[0049] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments.

[0050] Description of Figure Numbers:

[0051] 10. Main beam; 20. Cap beam; 210. Inverted U-shaped steel bar; 211. Transverse steel bar segment; 212. Side limb segment; 220. Cap beam connection assembly; 221. Ductile concrete connection segment; 222. Third shape memory alloy layer; 223. Z-shaped shape memory alloy rod; 2231. Middle working segment; 2232. Side connection segment; 30. Pier column; 311. First central bearing column; 312. First shape memory alloy layer; 313. First tubular ductile segment; 314. First annular steel plate; 315. Second annular steel plate; 321. Pier column body; 322, longitudinal main reinforcement of the pier column; 331, second central bearing column; 332, second shape memory alloy layer; 333, second tubular ductile section; 334, third annular steel plate; 335, fourth annular steel plate; 336, vent; 340, first stiffening plate; 350, second stiffening plate; 360, third stiffening plate; 370, fourth stiffening plate; 380, column tie beam; 381, X-shaped SMA rod; 382, ​​surface SMA expansion mesh; 383, ECC ductile concrete section; 40, pile foundation; 410, longitudinal main reinforcement of pile foundation; 420, pile tie beam. DETAILED DESCRIPTION

[0052] 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.

[0053] 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.

[0054] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) 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.

[0055] 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.

[0056] Please see attached Figures 1 to 4 In one embodiment of the present invention, a high-intensity earthquake zone bridge comprises a main beam 10, a cap beam 20, a pier 30 and a pile foundation 40 connected in sequence from top to bottom, wherein the pier 30 comprises an upper connecting section (not shown in the figure), an intermediate main section (not shown in the figure) and a lower connecting section (not shown in the figure) connected in sequence along the vertical direction, wherein:

[0057] It should be noted that the main beam 10, the cap beam 20, the pier 30 and the pile foundation 40 can be connected by prefabricated assembly or by cast-in-place connection. As a preferred embodiment, a cast-in-place construction method for bridges in high-intensity earthquake zones is given later in this application for reference by technical personnel in this field.

[0058] The upper connecting section includes a first central bearing column 311, a first shape memory alloy layer 312, a first tubular ductile section 313 located in the plastic hinge area, and a first annular steel plate 314 and a second annular steel plate 315 connected to the outer peripheral wall of the first central bearing column 311, wherein the upper end of the first central bearing column 311 extends into the interior of the cap beam 20 and is connected to the cap beam 20, and the lower end of the first central bearing column 311 is arranged in the middle main section; the first tubular ductile section 313 is connected to the outer peripheral wall of the first central bearing column 311, The structural strength of the first tubular ductile section 313 is less than that of the first central bearing column 311; the first annular steel plate 314 is located at the interface between the first tubular ductile section 313 and the cap beam 20, and the second annular steel plate 315 is located at the interface between the first tubular ductile section 313 and the intermediate main section; the first shape memory alloy layer 312 is tubular and is disposed in the first tubular ductile section 313, and the first shape memory alloy layer 312, the first tubular ductile section 313 and the first central bearing column 311 are coaxially arranged;

[0059] The lower connecting section includes a second central bearing column 331, a second shape memory alloy layer 332, a second tubular ductile section 333 located in the plastic hinge area, and a third annular steel plate 334 and a fourth annular steel plate 335 connected to the outer peripheral wall of the second central bearing column 331, wherein the lower end of the second central bearing column 331 extends into the interior of the pile foundation 40 and is connected to the pile foundation 40, and the upper end of the second central bearing column 331 is arranged in the middle main section; the second tubular ductile section 333 is connected to the outer peripheral wall of the second central bearing column 331, and the The structural strength of the second tubular ductile section 333 is less than the structural strength of the second central bearing column 331; the third annular steel plate 334 is located at the interface between the second tubular ductile section 333 and the pile foundation 40, and the fourth annular steel plate 335 is located at the interface between the second tubular ductile section 333 and the intermediate main section; the second shape memory alloy layer 332 is tubular and is arranged in the second tubular ductile section 333, and the second shape memory alloy layer 332, the second tubular ductile section 333 and the second central bearing column 331 are arranged coaxially.

[0060] It is worth noting that the first central bearing column 311 serves as the core bearing part of the upper docking section, and the second central bearing column 331 serves as the core bearing part of the lower docking section. The first central bearing column 311 and the second central bearing column 331 are preferably steel cylinders or steel short columns, which not only have high compressive strength, but also have good shear and bending resistance, and can maintain the stability of the structure under complex stress conditions, thereby improving the seismic performance; the first central bearing column 311 and the second central bearing column 331 form a strongly constrained section, such as a steel cylinder, which can give full play to the strength characteristics of constrained concrete, and the strength of the steel cylinder can reach or exceed the conventional section of the reinforced concrete pier 30; the outer side of the first central bearing column 311 and the second central bearing column 331 can only be arranged with a single layer of shape memory alloy, without the need for complex longitudinal and transverse steel meshes and their connections.

[0061] The first tubular ductile section 313 and the second tubular ductile section 333 are control areas for deformation and damage caused by strong earthquakes. In order to avoid damage in small earthquakes and be repairable in medium earthquakes, ECC ductile concrete is preferably used, which has high ductility, high strength, high durability and excellent seismic resistance. Secondly, the structural strength of the first tubular ductile section 313 is less than the structural strength of the first central bearing column 311. In this case, when a larger earthquake occurs, the first tubular ductile section 313 will be destroyed before the first central bearing column 311, thereby achieving the purpose of controllable damage area. The structural strength of the second tubular ductile section 333 is less than the structural strength of the second central bearing column 331. In this case, when a larger earthquake occurs, the second tubular ductile section 333 will be destroyed before the second central bearing column 331, thereby achieving the purpose of controllable damage area.

[0062] In addition, since the tubular ductile section and the shape memory alloy layer are arranged circumferentially on the outside of the central bearing column, according to the stress characteristics of the cross-section, the outer edge is subjected to greater stress, and the energy dissipation function of the tubular ductile section can be fully utilized, thereby protecting the central bearing column from damage.

[0063] The first shape memory alloy layer 312 and the second shape memory alloy layer 332 are preferably Fe-SMA iron-based shape memory metal expansion mesh, which has super elastic memory and good self-reset performance, and can form a combined force system with the external tubular ductile section (such as ECC ductile concrete), laying a solid foundation for prefabricated and assembled bridge piers to adapt to strong earthquake areas. The shape memory alloy layer can effectively constrain the tubular ductile section, and under the action of a smaller earthquake, the plastic hinge area can restore itself to its original state without special treatment such as special repair.

[0064] The central bearing column and the annular steel plate can be connected by an annular weld, and the longitudinal main reinforcement 322 of the pier column is connected to the annular steel plate, which serves as a key conversion component for the axial force transmission of the pier column 30. At the same time, vent holes 336 can be arranged at intervals on the annular steel plate to break the airtightness of the potential bubble generation area and ensure the reliable compaction of the concrete under the plate. In addition, the annular steel plate can still be used as a positioning frame for the steel frame, and is matched and manufactured with the longitudinal reinforcement of the pier column 30 in the factory, and has multiple functions.

[0065] The shape memory alloy layer, the tubular ductile section and the central bearing column are two systems that are jointly stressed but relatively independent. For example, during construction, the outer ring ECC ductile concrete is poured later, and the axial load of pier 30 is mainly borne by the central bearing column. The ECC ductile concrete mainly bears the bending moment load caused by variable loads such as automobiles and earthquakes. Therefore, ductile concrete with a relatively low grade can be used to meet daily stress needs. At the same time, ductile concrete with a relatively low grade also ensures the relative fixation of the plastic hinge position, effectively protecting the components.

[0066] Working process: When the earthquake force is small, the tubular ductile sections (such as ECC ductile concrete) in the plastic hinge area at the upper and lower ends of the pier, the central bearing column (such as steel cylinder or steel section) and the shape memory alloy layer (such as Fe-SMA iron-based shape memory expansion network) cooperate to deform and work together to consume earthquake energy, thereby ensuring that small earthquakes will not cause damage; 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 consume energy, so as to facilitate subsequent targeted repair of the area; in the event of a large earthquake, even if the first tubular ductile section 313 and the second tubular ductile section 333 are crushed and destroyed, the first central The 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 support the 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, that is, it has good self-stability after the earthquake. After the outer ductile concrete is removed, no additional structural support measures are required, which avoids the need to set up complex hoop structures and support systems for conventional structural repairs. The repair construction is convenient, the construction period and cost are saved, and the design goals of not being damaged by small earthquakes, being repairable by medium earthquakes, and not collapsing by large earthquakes can be achieved economically and reasonably.

[0067] In addition, this application does not require the installation of external auxiliary devices, has low anti-corrosion requirements, and requires less daily maintenance, which is basically consistent with the maintenance of reinforced concrete structures. No additional isolation measures are required, and the components of each part of the structure can withstand a certain external force, without obvious weak links, and the space under the bridge can be fully developed and utilized on a daily basis.

[0068] Preferably, the outer contour of the first tubular ductile section 313 and the second tubular ductile section 333 can be kept consistent with the pier 30, and can be cast normally after being welded to the pile foundation 40 or the cap beam 20 with embedded steel bars, without the need for templates of additional size, and the first tubular ductile section 313 and the second tubular ductile section 333 (such as ECC ductile concrete) can be cured together with conventional concrete.

[0069] As a preferred embodiment, a plurality of inverted U-shaped steel bars 210 surrounding the first central bearing column 311 are arranged in the cap beam 20, and each of the inverted U-shaped steel bars 210 includes a transverse steel bar segment 211 arranged on the top of the first central bearing column 311 and two side limb segments 212 respectively connected to both sides of the first central bearing column 311, wherein each of the side limb segments 212 extends downward from the transverse steel bar segment 211 and is connected to the first annular steel plate 314.

[0070] Specifically, Figure 3As shown, each inverted U-shaped steel bar 210 includes a transverse steel bar segment 211 and two side limb segments 212. The transverse steel bar segment 211 is arranged on the top of the first central bearing column 311 and arranged in the prefabricated cap beam 20 to play a role of connection and support. The two side limb segments 212 are respectively arranged on both sides of the first central bearing column 311, extending downward from the transverse steel bar segment 211 and extending into the first tubular ductile segment 313. The side limb segments 212 and the first annular steel plate 314 are connected as a whole, and the inverted U-shaped steel bar 210 spans the first central bearing column 311. The inverted U-shaped steel bar 210 can play a dual role of connection and shear resistance, and is reliable in force. This structure helps to maintain the overall stability and bearing capacity of the bridge structure under earthquakes or other external forces.

[0071] As a preferred embodiment, the top of the longitudinal main reinforcement 410 of the pile foundation is connected to the third annular steel plate 334, and / or the intermediate main section includes a pier body 321 and a pier longitudinal main reinforcement 322 arranged in the pier body 321, the top of the pier longitudinal main reinforcement 322 is connected to the second annular steel plate 315, and the bottom of the pier longitudinal main reinforcement 322 is connected to the fourth annular steel plate 335.

[0072] Specifically, the top of the longitudinal main reinforcement 410 of the pile foundation is connected to the third annular steel plate 334. Under the action of earthquake or load, the force exerted on the pile foundation 40 can be directly transmitted to the third annular steel plate 334 through the longitudinal main reinforcement, and then dispersed to other force-bearing components of the pier column 30. The top of the longitudinal main reinforcement 322 of the pier column is connected to the second annular steel plate 315, and the bottom is connected to the fourth annular steel plate 335, so that the longitudinal main reinforcement of the pier column 30 becomes an integral force-bearing system, which enhances the longitudinal bearing capacity of the pier column 30 and can also provide better restraint and stability during earthquakes.

[0073] As a preferred embodiment, the first annular steel plate 314 , the second annular steel plate 315 , the third annular steel plate 334 , and the fourth annular steel plate 335 are all provided with ventilation holes 336 .

[0074] Specifically, by opening air holes 336 in the first annular steel plate 314, the second annular steel plate 315, the third annular steel plate 334, and the fourth annular steel plate 335, the number and arrangement of the air holes 336 can be set according to actual needs. Preferably, the number of the air holes 336 is set to multiple, and they are evenly spaced along the circumference of the annular steel plate. The air holes 336 break the airtightness of the potential bubble generation area, thereby ensuring the reliable compaction of the concrete under the plate.

[0075] Furthermore, it also includes a plurality of first stiffening plates 340 and second stiffening plates 350 connected (preferably welded) to the outer peripheral wall of the first central bearing column 311, and a plurality of third stiffening plates 360 and fourth stiffening plates 370 connected (preferably welded) to the outer peripheral wall of the second central bearing column 331, the first stiffening plate 340 is arranged in the cap beam 20 and the bottom of the first stiffening plate 340 is connected to the first annular steel plate 314 (preferably welded), the second stiffening plate 350 is arranged in the middle main body section and the top of the second stiffening plate 350 is connected to the second annular steel plate 315 (preferably welded), the third stiffening plate 360 ​​is arranged in the pile foundation 40 and the top of the third stiffening plate 360 ​​is connected to the third annular steel plate 334 (preferably welded), and the fourth stiffening plate 370 is arranged in the middle main body section and the bottom of the fourth stiffening plate 370 is connected to the fourth annular steel plate 335 (preferably welded).

[0076] Specifically, by providing the first stiffening plate 340, the second stiffening plate 350, the third stiffening plate 360 ​​and the fourth stiffening plate 370, the overall structural strength can be enhanced, and under the action of an earthquake or other external force, the ability to resist and disperse external forces can be improved, thereby improving the overall stability, safety and seismic resistance of the bridge structure.

[0077] As a preferred embodiment, the number of the cap beam 20, the pier 30 and the pile foundation 40 along the transverse direction of the bridge is two, wherein when the height of the pier 30 is less than 5m, the two cap beams 20 are connected by a cap beam 20 connecting assembly, the cap beam 20 connecting assembly includes a ductile concrete connecting section 221, a third shape memory alloy layer 222 coated on the outer surface of the ductile concrete connecting section 221, and a plurality of reset assemblies arranged at intervals along the longitudinal direction of the bridge, each of the reset assemblies includes two symmetrically arranged Z-shaped shape memory alloy rods 223, the two Z-shaped shape memory alloy rods 223 form an X-shaped structure, each of the Z-shaped shape memory alloy rods 223 includes a middle working section 2231 arranged in the ductile concrete connecting section 221 and two side connecting sections 2232 connected to the two ends of the middle section, and each side connecting section 2232 is respectively arranged in the corresponding cap beam 20.

[0078] Specifically, when the height of the pier 30 is less than 5m, the two cap beams 20 are connected by the cap beam 20 connection assembly to form a stable overall structure. This connection method not only improves the seismic performance of the bridge, but also enhances the overall stability and durability of the structure. The cap beam 20 connection assembly mainly includes a ductile slow concrete connection section, a third shape memory alloy layer 222 and a plurality of reset assemblies. As the main connector, the ductile slow concrete connection section has good ductility and toughness, and can absorb and disperse external forces. The third shape memory alloy layer 222 is coated on the outer surface of the ductile slow concrete connection section. By utilizing the characteristics of the shape memory alloy, it can be restored to its original shape after being subjected to external forces, thereby enhancing the self-resetting ability of the connection assembly. The reset assembly is composed of two symmetrically arranged Z-shaped shape memory alloy rods 223 to form an X-shaped structure. This structure can provide additional reset force and stability through the deformation and recovery of the shape memory alloy rods when subjected to external forces.

[0079] Each Z-shaped shape memory alloy rod 223 includes a middle working section 2231 and two side connecting sections 2232. The middle working section 2231 is arranged in the ductile slow concrete connecting section, and the side connecting sections 2232 are respectively arranged in the corresponding cap beam 20. This layout enables the shape memory alloy rod to tightly connect the cap beam 20 and the ductile slow concrete connecting section. When the bridge is subjected to external forces, such as earthquakes, the shape memory alloy rod will deform. Once the external force disappears, the shape memory alloy rod will use its memory effect to restore to its original shape, thereby driving the ductile slow concrete connecting section and the cap beam 20 to restore to their original positions together, realizing the self-reset function, thereby ensuring self-reset for small and medium earthquakes. During a large earthquake, the shape memory alloy rod is deformed to actively weaken the connection of the cap beam 20 (transmit shear but not bending), and the ductile slow concrete connecting section consumes energy.

[0080] Preferably, the shape memory alloy rod is a Fe-SMA rod, the third shape memory alloy layer 222 is a Fe-SMA iron-based shape memory extended net, the cap beams 20 are connected by X-shaped Fe-SMA rods, and a Fe-SMA extended net is provided on the outer surface of the ductile concrete connection section 221 to ensure self-resetting in small and medium earthquakes. In the event of a large earthquake, the X-shaped Fe-SMA rod is deformed to actively weaken the connection of the cap beam 20 (shear is transmitted but not bending), and energy is dissipated by the ductile concrete.

[0081] As another preferred embodiment, the number of the cap beam 20, the pier 30 and the pile foundation 40 along the transverse direction of the bridge is two. When the height of the pier 30 is 5 to 15 m, the two cap beams 20 are connected by a cap beam 20 connection assembly, and the two pile foundations 40 are rigidly connected by a pile tie beam 420; wherein the cap beam 20 connection assembly includes a ductile concrete connection section 221, a third shape memory alloy layer 222 coated on the outer surface of the ductile concrete connection section 221, and a plurality of reset assemblies arranged at intervals along the longitudinal direction of the bridge, each of the reset assemblies includes two symmetrically arranged Z-shaped shape memory alloy rods 223, and the two Z-shaped shape memory alloy rods 223 form an X-shaped structure, and each Z-shaped shape memory alloy rod 223 includes a middle working section 2231 arranged in the ductile concrete connection section 221 and two side connection sections 2232 connected to the two ends of the middle section, and each side connection section 2232 is respectively arranged in the corresponding cap beam 20.

[0082] Specifically, when the height of the pier 30 is 5 to 15 m, the two cap beams 20 are connected by a cap beam 20 connecting assembly, and the two pile foundations 40 are rigidly connected by a pile tie beam 420, which can further improve the stability and seismic resistance of the bridge.

[0083] As another embodiment, the number of the cap beam 20, the pier 30 and the pile foundation 40 along the transverse direction of the bridge is two. When the height of the pier 30 is greater than 15m, the two cap beams 20 are connected by the cap beam 20 connection assembly, the two pile foundations 40 are rigidly connected by the pile tie beam 420, and the two piers 30 are connected by the column tie beam 380; wherein,

[0084] The cap beam 20 connection assembly includes a ductile concrete connection section 221, a third shape memory alloy layer 222 coated on the outer surface of the ductile concrete connection section 221, and a plurality of reset assemblies arranged at intervals along the longitudinal bridge direction, each of the reset assemblies includes two symmetrically arranged Z-shaped shape memory alloy rods 223, the two Z-shaped shape memory alloy rods 223 form an X-shaped structure, each of the Z-shaped shape memory alloy rods 223 includes a middle working section 2231 arranged in the ductile concrete connection section 221 and two side connection sections 2232 connected to the two ends of the middle section, and each side connection section 2232 is respectively arranged in the corresponding cap beam 20;

[0085] Specifically, when the height of the pier 30 is less than 15m, the two cap beams 20 are connected by the cap beam 20 connection assembly to form a stable overall structure. This connection method not only improves the seismic performance of the bridge, but also enhances the overall stability and durability of the structure. The cap beam 20 connection assembly mainly includes a ductile slow concrete connection section 221, a third shape memory alloy layer 222 and a plurality of reset assemblies. As the main connector, the ductile slow concrete connection section 221 has good ductility and toughness, and can absorb and disperse external forces. The third shape memory alloy layer 222 is coated on the outer surface of the ductile slow concrete connection section 221. By utilizing the characteristics of the shape memory alloy, it can be restored to its original shape after being subjected to external forces, thereby enhancing the self-resetting ability of the connection assembly. The reset assembly is composed of two symmetrically arranged Z-shaped shape memory alloy rods 223 to form an X-shaped structure. This structure can provide additional reset force and stability through the deformation and recovery of the shape memory alloy rods when subjected to external forces.

[0086] Each Z-shaped shape memory alloy rod 223 includes a middle working section 2231 and two side connecting sections 2232. The middle working section 2231 is arranged in the ductile slow concrete connecting section 221, and the side connecting sections 2232 are respectively arranged in the corresponding cap beam 20. This layout enables the shape memory alloy rod to tightly connect the cap beam 20 and the ductile slow concrete connecting section. When the bridge is subjected to external forces, such as earthquakes, the shape memory alloy rod will deform. Once the external force disappears, the shape memory alloy rod will use its memory effect to restore to its original shape, thereby driving the ductile slow concrete connecting section 221 and the cap beam 20 to return to their original positions together, realizing the self-reset function.

[0087] In this embodiment, when the height of the pier 30 is 5 to 15 m, multiple transverse connections are arranged from top to bottom between the piers to ensure that the columns are subjected to coordinated force: the low-grade ECC connection sections between the cap beams 20 are weakly connected, which can achieve node deformation and energy dissipation; the rigid connection of the pile-tied beam 420 ensures the integrity of the foundation and reliable force.

[0088] Furthermore, the column tie beam 380 is composed of a reinforced concrete structure in the middle, an X-shaped SMA rod 381 arranged at both ends, and an ECC ductile concrete segment 383 of a surface SMA expansion net 382. When the tie beam is prefabricated: the reinforced concrete column tie beam 380 is prefabricated in the factory, and the X-shaped SMA rods 381 are extended at both ends for embedding in the cast-in-place pier column 30. After the column tie beam 380 is hoisted in place, the concrete of the pier column 30 is cast in a formwork. The column tie beam 380 uses the stress-deformation characteristics of the ECC ductile concrete segment 383 and the X-shaped SMA rod 381 to achieve a light semi-rigid connection between the pier columns 30.

[0089] The present invention also provides a construction method for a bridge in a high-intensity earthquake zone, which is applied to the above-mentioned bridge in a high-intensity earthquake zone and comprises the following steps:

[0090] S1, drilling / punching holes for pile foundation 40, making and hoisting steel cage for pile foundation 40 in the factory, pouring concrete for pile foundation 40, removing scum concrete and over-cast concrete above the pile top, and then pouring pile tie beam 420;

[0091] S2, tie up the steel cage of pier column 30, hoist the column tie beam 380, and pour the concrete of pier column 30;

[0092] S3, tying the steel mesh of the cap beam 20, fixing the reset assembly, and pouring the ordinary concrete of the cap beam 20;

[0093] S4, installing the first shape memory alloy layer 312, the second shape memory alloy layer 332, and the third shape memory alloy layer 222, and pouring the first tubular ductile section 313, the second tubular ductile section 333, and the ductile concrete connecting section 221 in sequence from bottom to top to complete the pier construction;

[0094] S5, construct the bridge superstructure and bridge deck system, complete the bridge construction, and open it to traffic.

[0095] The present invention also provides a post-earthquake repair method for a bridge in a high-intensity earthquake zone, which is applied to the above-mentioned bridge in a high-intensity earthquake zone and comprises the following steps:

[0096] 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, whether the second tubular ductile section 333 meets the second repair condition, and whether the ductile concrete connecting section 221 meets the third repair condition;

[0097] Specifically, the first repair condition may be that a crack width greater than 0.2 mm appears on the surface of the first tubular ductile section 313 or a local concrete collapse 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 the following conditions: The third repair condition can be that the crack width is greater than 0.2 mm, or the concrete falling area is greater than 2 cm 2 , or any one or more of the following: significant residual deformation of the connected components.

[0098] When the first tubular ductile section 313 meets the first repair condition, the damaged portion of the first tubular ductile section 313 is chiseled out, and the interface is cleaned and roughened with a high-pressure water gun; the residual deformation of the first shape memory alloy layer 312 is then checked, and when the residual deformation of the first shape memory alloy layer 312 exceeds the first preset threshold or is damaged, the first shape memory alloy layer 312 is removed and the remaining first tubular ductile section 313 is chiseled out, and the first shape memory alloy layer 312 that meets the quality requirements is replaced, and the first tubular ductile section 313 is re-cast and cured to form a full-section stress state of the pier column 30 joint;

[0099] When the second tubular ductile section 333 meets the second repair condition, the damaged portion of the second tubular ductile section 333 is chiseled out, and the interface is cleaned and roughened with a high-pressure water gun; the residual deformation of the second shape memory alloy layer 332 is then checked, and when the residual deformation of the second shape memory alloy layer 332 exceeds the second preset threshold or is damaged, the second shape memory alloy layer 332 is removed and the remaining second tubular ductile section 333 is chiseled out, and the second shape memory alloy layer 332 that meets the quality requirements is replaced, and the second tubular ductile section 333 is recast and cured to form a full-section stress state of the pier column 30 joint;

[0100] When the ductile concrete connection section 221 meets the third repair condition, the third shape memory alloy layer 222 is removed for standby, the ductile concrete connection section 221 is removed, and the reset assembly is protected, the third shape memory alloy layer 222 is reinstalled, and the ductile concrete connection section 221 is recast and cured to form the overall stress state of the pier cap beam 20;

[0101] Repair other ancillary structures of the bridge and resume traffic operation.

[0102] Specifically, it will be launched immediately after the post-earthquake rescue work is completed. By closing the bridge traffic, assessing the damage and taking targeted repair measures, the bridge's traffic capacity can be quickly restored, which is crucial for emergency rescue and post-disaster reconstruction after natural disasters such as earthquakes.

[0103] During the repair process, the interface was cleaned and roughened by a high-pressure water gun to improve the bonding strength of the new and old materials; the first shape memory alloy layer 312 and the second shape memory alloy layer 332 that met the quality requirements were replaced to ensure that the repaired structure had good self-recovery performance; the integrity and stress performance of the structure were restored by re-casting the first tubular ductile section 313, the second tubular ductile section 333 and the ductile slow-setting soil connection section and curing. Necessary protective measures were taken when chiseling out the damaged part to avoid secondary damage to the surrounding structure; when replacing the shape memory alloy layer mesh and pouring new concrete, the quality of the materials and the construction process were strictly controlled to ensure that the repaired structure met the design requirements and usage requirements.

[0104] 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 in a high-intensity earthquake zone, characterized in that: It includes a main beam, a cap beam, a pier column and a pile foundation connected in sequence from top to bottom, and the pier column includes an upper connecting section, an intermediate main section and a lower connecting section connected in sequence along the vertical direction, wherein: The upper connecting section includes a first central bearing column, a first shape memory alloy layer, a first tubular ductile section located in a plastic hinge area, and a first annular steel plate and a second annular steel plate connected to the outer peripheral wall of the first central bearing column, wherein the upper end of the first central bearing column extends into the pier column and is connected to the cap beam, and the lower end of the first central bearing column is connected to the middle main section; the first tubular ductile section is connected to the outer peripheral wall of the first central bearing column, and the structural strength of the first tubular ductile section is less than the structural strength of the first central bearing column; the first annular steel plate is located at the interface between the first tubular ductile section and the cap beam, and the second annular steel plate is located at the interface between the first tubular ductile section and the middle main section; the first shape memory alloy layer is tubular and is arranged in the first tubular ductile section, and the first shape memory alloy layer, the first tubular ductile section and the first central bearing column are arranged coaxially; The lower connecting section includes a second central bearing column, a second shape memory alloy layer, a second tubular ductile section located in the plastic hinge area, and a third annular steel plate and a fourth annular steel plate connected to the outer peripheral wall of the second central bearing column, wherein the lower end of the second central bearing column extends into the pier and is connected to the pile foundation, and the upper end of the second central bearing column is connected to the middle main section; the second tubular ductile section is connected to the outer peripheral wall of the second central bearing column, and the structural strength of the second tubular ductile section is less than the structural strength of the second central bearing column; the third annular steel plate is located at the interface between the second tubular ductile section and the pile foundation, and the fourth annular steel plate is located at the interface between the second tubular ductile section and the middle main section; the second shape memory alloy layer is tubular and is arranged in the second tubular ductile section, and the second shape memory alloy layer, the second tubular ductile section and the second central bearing column are arranged coaxially.

2. The high-intensity earthquake zone bridge according to claim 1, characterized in that: A plurality of inverted U-shaped steel bars surrounding the first central bearing column are arranged in the cap beam, and each of the inverted U-shaped steel bars includes a transverse steel bar segment arranged on the top of the first central bearing column and two side limb segments respectively connected to both sides of the first central bearing column, wherein each of the side limb segments extends downward from the transverse steel bar segment and is connected to the first annular steel plate.

3. The high-intensity earthquake zone bridge according to claim 2, characterized in that: The top of the longitudinal main reinforcement of the pile foundation is connected to the third annular steel plate, and / or the intermediate main section includes a pier body and pier longitudinal main reinforcements arranged in the pier body, the top of the pier longitudinal main reinforcement is connected to the second annular steel plate, and the bottom of the pier longitudinal main reinforcement is connected to the fourth annular steel plate.

4. The high-intensity earthquake zone bridge according to claim 1, characterized in that: The first annular steel plate, the second annular steel plate, the third annular steel plate, and the fourth annular steel plate are all provided with ventilation holes.

5. The high-intensity earthquake zone bridge according to claim 3, characterized in that: It also includes a plurality of first and second stiffening plates connected to the outer peripheral wall of the first central bearing column, and a plurality of third and fourth stiffening plates connected to the outer peripheral wall of the second central bearing column, the first stiffening plate is arranged in the cap beam and the bottom of the first stiffening plate is connected to the first annular steel plate, the second stiffening plate is arranged in the middle main body section and the top of the second stiffening plate is connected to the second annular steel plate, the third stiffening plate is arranged in the pile foundation and the top of the third stiffening plate is connected to the third annular steel plate, and the fourth stiffening plate is arranged in the middle main body section and the bottom of the fourth stiffening plate is connected to the fourth annular steel plate.

6. The high-intensity earthquake zone bridge according to claim 5, characterized in that: The number of the cap beam, pier and pile foundation along the transverse direction of the bridge is two, wherein when the height of the pier is less than 5m, the two cap beams are connected by a cap beam connection assembly, the cap beam connection assembly includes a ductile concrete connection section, a third shape memory alloy layer coated on the outer surface of the ductile concrete connection section, and a plurality of reset assemblies arranged at intervals along the longitudinal direction of the bridge, each of the reset assemblies includes two symmetrically arranged Z-shaped shape memory alloy rods, the two Z-shaped shape memory alloy rods cross to form an X-shaped structure, each of the Z-shaped shape memory alloy rods includes a middle working section arranged in the ductile concrete connection section and two side connecting sections connected to both ends of the middle working section, and each side connecting section is respectively arranged in the corresponding cap beam.

7. The high-intensity earthquake zone bridge according to claim 5, characterized in that: The number of the cap beam, pier and pile foundation along the transverse direction of the bridge is two. When the height of the pier is 5 to 15m, the two cap beams are connected by a cap beam connection assembly, and the two pile foundations are rigidly connected by a pile tie beam; wherein the cap beam connection assembly includes a ductile concrete connection section, a third shape memory alloy layer coated on the outer surface of the ductile concrete connection section, and a plurality of reset assemblies arranged at intervals along the longitudinal direction of the bridge, each of the reset assemblies includes two symmetrically arranged Z-shaped shape memory alloy rods, and the two Z-shaped shape memory alloy rods cross to form an X-shaped structure, and each of the Z-shaped shape memory alloy rods includes a middle working section arranged in the ductile concrete connection section and two side connecting sections connected to the two ends of the middle working section, and each side connecting section is respectively arranged in the corresponding cap beam.

8. The high-intensity earthquake zone bridge according to claim 5, characterized in that: The number of the cap beam, pier column and pile foundation along the transverse direction of the bridge is two. When the height of the pier column is greater than 15m, the two cap beams are connected by a cap beam connection assembly, the two pile foundations are rigidly connected by a pile tie beam, and the two pier columns are connected by a column tie beam; wherein, The cap beam connection assembly includes a ductile concrete connection section, a third shape memory alloy layer coated on the outer surface of the ductile concrete connection section, and a plurality of reset assemblies spaced apart along the longitudinal bridge direction, each of the reset assemblies includes two symmetrically arranged Z-shaped shape memory alloy rods, the two Z-shaped shape memory alloy rods cross to form an X-shaped structure, each of the Z-shaped shape memory alloy rods includes a middle working section arranged in the ductile concrete connection section and two side connection sections connected to both ends of the middle working section, and each side connection section is respectively arranged in the corresponding cap beam.

9. A construction method for a bridge in a high-intensity earthquake zone, applied to the bridge in a high-intensity earthquake zone as claimed in claim 8, characterized in that: The following steps are involved: S1, drilling / punching holes for pile foundation, making and hoisting pile foundation steel cage in the factory, pouring pile foundation concrete, removing scum concrete and over-cast concrete above the pile top, and then pouring pile tie beam; S2, tie up the pier column reinforcement cage, hoist the column tie beam, and pour the pier column concrete; S3, tying the cap beam reinforcement mesh, fixing the reset assembly, and pouring the cap beam ordinary concrete; S4, installing the first shape memory alloy layer, the second shape memory alloy layer, and the third shape memory alloy layer, and pouring the first tubular ductile section, the second tubular ductile section, and the ductile concrete connecting section in sequence from bottom to top to complete the pier construction; S5, construct the bridge superstructure and bridge deck system, complete the bridge construction, and open it to traffic.

10. A post-earthquake repair method for a bridge in a high-intensity earthquake zone, applied to the bridge in a high-intensity earthquake zone as claimed in claim 8, characterized in that: The following steps are involved: 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 the first repair condition, whether the second tubular ductile section meets the second repair condition, and whether the ductile concrete connecting section meets the third repair condition; When the first tubular ductile section meets the first repair condition, the damaged portion of the first tubular ductile section is chiseled out, and the interface is cleaned and roughened with a high-pressure water gun; the residual deformation of the first shape memory alloy layer is then checked, and when the residual deformation of the first shape memory alloy layer mesh exceeds the first preset threshold or is damaged, the first shape memory alloy layer mesh is removed and the remaining first tubular ductile section is chiseled out, and the first shape memory alloy layer mesh that meets the quality requirements is replaced, and the first tubular ductile section is recast and cured to form a full-section stress state of the pier column joint; When the second tubular ductile section meets the second repair condition, the damaged portion of the second tubular ductile section is chiseled out, and the interface is cleaned and roughened with a high-pressure water gun; the residual deformation of the second shape memory alloy layer is checked again, and when the residual deformation of the second shape memory alloy layer mesh exceeds the second preset threshold or is damaged, the second shape memory alloy layer mesh is removed and the remaining second tubular ductile section is chiseled out, and the second shape memory alloy layer mesh that meets the quality requirements is replaced, and the second tubular ductile section is recast and cured to form a full-section stress state of the pier column joint; When the ductile concrete connection section meets the third repair condition, the third shape memory alloy layer is removed for standby, the ductile concrete connection section is removed, and the reset assembly is protected, the third shape memory alloy layer is reinstalled, and the ductile concrete connection section is re-cast and cured to form the overall stress state of the bridge pier cap beam; Repair other ancillary structures of the bridge and resume traffic operation.

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