High-intensity area stainless steel-ECC assembly type pier column-foundation node connecting structure and construction method

Abstract

The invention relates to a high-intensity area stainless steel-ECC assembly type pier column-foundation joint connecting structure and a construction method, and belongs to the technical field of structural engineering. Comprising a prefabricated concrete pier column and a concrete foundation, and the good anti-seismic performance of the joint is guaranteed in the mode of high-strength stainless steel bar grouting sleeve connection and UHPC grouting socket and spigot joint combined connection; the prefabricated concrete pier column is composed of common concrete, pier body longitudinal common steel bars, pier body common stirrups, ECC concrete, pier body longitudinal stainless steel bars, pier body longitudinal high-strength stainless steel bars, pre-buried grouting sleeves, pre-buried grouting pipes, pre-buried grout outlet pipes and pier body FRP stirrups. The concrete foundation is jointly composed of reserved high-strength stainless steel bars, reserved socket grooves, foundation longitudinal steel bars, annular stirrups and foundation stirrups. The method can break through the bottleneck problem of limiting the connection reliability and the anti-seismic safety of the fabricated bridge pier joint in the high-intensity area, is popularized to new construction and reconstruction and extension of bridges and ocean engineering structures in the high-intensity area, and has a wide application prospect.

Description

Technical Field

[0001] The invention relates to an assembled pier column-foundation node connection structure, in particular to a high-intensity zone stainless steel-ECC assembled pier column-foundation node connection structure and a construction method, belonging to the technical field of structural engineering. Background Art

[0002] Transportation is a basic, leading and strategic industry in the national economy. It is an important service industry and an important part of the modern economic system. With the acceleration of urbanization and the continuous improvement of transportation infrastructure, bridge construction faces more and more challenges. It is urgent to improve the efficiency and quality of bridge construction and promote the use of bridges in high-intensity marine environments. Traditional pier construction technology has disadvantages such as long construction period, large investment in manpower and material resources, and difficulty in quality control. It is difficult to adapt to the requirements of modern bridge construction for environmental protection and sustainable development. The prefabricated assembly construction technology adopts the construction method of factory processing components and on-site assembly. It has the advantages of less environmental pollution, less impact on traffic, short construction period, high construction quality and significant economic benefits, which can well meet the needs of modern bridge construction.

[0003] my country is a large maritime country and is located between the Pacific Rim seismic belt and the Eurasian seismic belt, with frequent earthquake activities in offshore areas. At the same time, the demand for new technologies for cross-sea bridges is increasing, and the pier-foundation node is a more important part of the entire bridge structure. Its seismic performance and corrosion resistance in high-intensity marine environments and rapid post-disaster repair are particularly important. At present, most of my country's bridge prefabricated substructure node connection technology is used in non-strong earthquake areas, and is relatively lacking in high-intensity marine environments. Therefore, a prefabricated pier-foundation connection structure suitable for high-intensity marine environments is urgently needed.

[0004] In the traditional prefabricated pier node connection technology, the socket connection has many advantages such as small construction precision, high component quality, short construction period, and good seismic performance. However, in order to ensure its seismic performance, its socket depth will increase, the foundation size will be large, and the foundation cost will be increased. At the same time, the prefabricated pier node is prone to rust in the marine environment, resulting in a significant reduction in its seismic performance, which limits its promotion and application in marine engineering. For example, CN110359363A discloses a partially bonded prestressed prefabricated self-resetting bridge pier node and method, including a pier, the main body of the pier is formed of concrete, the lower end of the pier is inserted into the foundation and fixedly connected to the foundation, and the upper end is fixedly connected to the cap beam. It also has the above-mentioned large socket depth and is not suitable for the marine environment.

[0005] Therefore, it is urgent to propose a new type of prefabricated pier-foundation node connection structure and construction method that can meet the seismic performance requirements and corrosion resistance of bridges in marine environments in high-intensity areas. Summary of the invention

[0006] In view of the above-mentioned defects in the above-mentioned prior art, the present invention proposes a stainless steel-ECC assembled pier-foundation node connection structure and construction method for high-intensity areas, which can not only meet the seismic performance and corrosion resistance of assembled pier-foundation node connection nodes in high-intensity marine environments, but also can significantly reduce the socket depth, thereby reducing the foundation cost, and has the characteristics of simple construction technology. At the same time, the node structure also has the advantages of good ductility, high energy consumption capacity, and rapid post-earthquake repair. Provide technical support for the promotion and application of prefabricated assembly construction technology in bridges and marine structure projects in cross-sea, highway and municipal areas in high-intensity areas.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] The high-intensity stainless steel-ECC assembled pier-foundation node connection structure is composed of a precast concrete pier and a concrete foundation, wherein the precast concrete pier socket is inserted into the socket of the concrete foundation;

[0009] The precast concrete pier column comprises an upper ordinary concrete pier column and a lower ECC concrete pier column, wherein the upper ordinary concrete pier column comprises a pier body longitudinal ordinary steel bar and a pier body ordinary stirrup which are cast together by ordinary concrete;

[0010] The lower ECC concrete pier column includes longitudinal stainless steel bars of the pier body, longitudinal high-strength stainless steel bars of the pier body, pre-embedded grouting sleeves, pre-embedded grouting pipes, pre-embedded grouting pipes and FRP stirrups of the pier body, which are wrapped and cast together with ECC concrete;

[0011] The longitudinal stainless steel bars of the pier body and the longitudinal ordinary steel bars of the pier body, as well as the longitudinal high-strength stainless steel bars of the pier body and the longitudinal ordinary steel bars of the pier body are vertically connected together through steel bar connectors; the lower ends of the longitudinal high-strength stainless steel bars of the pier body are inserted into the pre-embedded grouting sleeves; the pre-embedded grouting sleeves are pre-embedded at the bottom of the precast concrete pier column, and the side walls thereof are connected with the pre-embedded grouting pipes and the pre-embedded grouting outlet pipes extending to the surface of the concrete pier column;

[0012] The concrete foundation also includes foundation longitudinal steel bars, foundation stirrups and foundation reserved high-strength stainless steel bars. The foundation stirrups are arranged around the socket, penetrate the middle of the concrete foundation and overlap with the foundation longitudinal steel bars. The foundation reserved high-strength stainless steel bars are located at the bottom of the concrete foundation socket, and the top of the foundation extends out of the socket and is connected to the pier shaft longitudinal high-strength stainless steel bars through the pre-embedded grouting sleeve, and the lower end is anchored to the foundation longitudinal steel bars.

[0013] High-strength concrete UHPC is poured between the inner wall of the socket of the concrete foundation and the side wall of the bottom of the prefabricated pier column.

[0014] Furthermore, the length of the foundation reserved high-strength stainless steel bar inserted into the reserved grouting sleeve is not less than 5 times the diameter of the foundation reserved high-strength stainless steel bar; the diameter of the embedded grouting sleeve is not less than 2-3 times the diameter of the longitudinal high-strength stainless steel bar of the pier body.

[0015] Furthermore, the lengths of the pier shaft longitudinal common steel bars, pier shaft longitudinal stainless steel bars and pier shaft longitudinal high-strength stainless steel bars inserted into the steel bar connector are not less than 3 times the diameter of the pier shaft longitudinal stainless steel bars.

[0016] Furthermore, the thickness of the steel bar connector is not less than 2 mm.

[0017] Furthermore, the compressive strength of the high-strength concrete UHPC is not less than 120 MPa, and the tensile strength is not less than 10 MPa.

[0018] Furthermore, the number of high-strength stainless steel bars reserved in the foundation is 1 / 2-1 / 4 times the number of common longitudinal steel bars in the pier body; the socket depth of the precast concrete pier column is not less than 0.6 times the diameter of the precast concrete pier column.

[0019] Furthermore, the inner diameter of the pre-embedded grouting sleeve is 20-40 mm larger than the longitudinal high-strength stainless steel reinforcement of the pier body, and the thickness is not less than 2 mm; the inner diameter of the pre-embedded grouting pipe and the pre-embedded slurry outlet pipe is 20-40 mm, and the wall thickness is not less than 0.5 mm.

[0020] Furthermore, the pre-buried grouting pipe and the pre-buried grouting outlet pipe are respectively connected to the bottom and the top of the pre-buried grouting sleeve; the pre-buried grouting sleeve is evenly arranged on the circumference of the cross section of the lower ECC concrete pier column, and a plurality of longitudinal stainless steel bars of the pier body are arranged at intervals.

[0021] Furthermore, a 10-30 mm mortar layer is provided between the bottom surface of the precast concrete pier column and the bottom surface of the concrete foundation socket.

[0022] The construction method of the above-mentioned high-intensity zone stainless steel-ECC assembled pier-foundation node connection structure comprises the following steps:

[0023] S1. Tie the common longitudinal steel bars and common stirrups of the pier body in the factory. After the binding is completed, a steel mesh is formed. The formwork is supported. Ordinary concrete is poured. The specimen is cured. The formwork is removed to complete the production of the upper part of the pier column. Then, the steel connector is installed at the end of the reserved common longitudinal steel bars of the pier body. The stainless steel bars and high-strength stainless steel bars of the pier body are connected to the common longitudinal steel bars of the pier body through the steel connector. Then, the FRP stirrups of the pier body, the embedded grouting sleeves, the embedded grouting pipes and the embedded grouting pipes are tied to form a steel mesh at the lower part of the pier column. The formwork is supported. ECC concrete is poured. The specimen is cured. The formwork is removed to complete the production of the precast concrete pier column.

[0024] S2. Tie the foundation longitudinal steel bars and foundation stirrups of the concrete foundation on site, reserve sockets for the precast concrete piers, reserve and accurately position the foundation reserved high-strength stainless steel bars, and finally support the formwork and pour concrete to complete the production of the precast foundation;

[0025] S3. The precast concrete pier is transported to the construction site, a 10-30 mm thick grouting layer is laid on the bottom surface of the concrete foundation socket, the high-strength stainless steel bars reserved for the foundation extending out of the concrete foundation socket are inserted into the embedded grouting sleeve of the precast concrete pier, the horizontality and verticality of the precast concrete pier are adjusted, and the placement of the precast concrete pier is completed;

[0026] S4. Mix high-strength concrete UHPC on site, use high-pressure grouting equipment to fill the pre-buried grouting pipe with high-strength concrete UHPC, and use grouting method to pour high-strength concrete UHPC into the grouting sleeve through the pre-buried grouting pipe until the high-strength concrete UHPC overflows from the pre-buried slurry outlet to ensure that the high-strength concrete UHPC in the grouting sleeve is full; pour high-strength concrete UHPC between the bottom side wall of the precast concrete pier and the inner wall of the concrete foundation socket, so that the precast concrete pier and the concrete foundation are connected as a whole, completing the assembly of the precast concrete pier and the concrete foundation.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention adopts prefabricated assembly construction technology. The piers are produced and processed by the component factory and then transported to the construction site, which improves the construction quality of the components and reduces the construction site procedures. The prefabricated concrete piers and concrete foundations adopt a combined connection method of UHPC grouting sockets and grouting sleeves, which has the advantages of fast splicing, high fault tolerance and efficient connection, improves the industrialization level of building and bridge structure construction, and reduces energy consumption and environmental pollution.

[0029] 2. The bottom of the pier adopts a stainless steel bar-ECC concrete composite section. ECC has excellent damage tolerance, self-repair characteristics and durability in harsh environments. It can reduce the damage to the plastic hinge area of ​​the pier after the earthquake and realize the rapid recovery of the bridge's post-earthquake capacity. The stainless steel bar can achieve good corrosion resistance of the pier in rusty environments such as the ocean, greatly reducing the degradation of the mechanical properties of the pier caused by adverse environments such as corrosion. Combined with ECC materials, it can greatly ensure the good seismic performance of the pier in medium and high intensity marine environments.

[0030] 3. The use of ultra-high performance concrete (UHPC) as grouting material for the socket connection between piers and caps can effectively improve the bonding performance and shear resistance between the piers and caps and the existing concrete interface, and enhance the safety and reliability of the interface connection under long-term loads (self-weight, vehicles) and accidental loads (earthquakes, impacts).

[0031] 4. The bottom section of the pier column adopts a combination of high-strength stainless steel longitudinal reinforcement and ordinary stainless steel longitudinal reinforcement. The high-strength stainless steel reinforcement accounts for only 1 / 2 to 1 / 4 of the total longitudinal reinforcement. The grouting sleeve is embedded in the high-strength stainless steel reinforcement and connected with the high-strength stainless steel reinforcement grouting reserved at the corresponding position in the pedestal, which greatly ensures the splicing efficiency and quality, and improves the reliability and pull-out resistance of the node connection.

[0032] 5. Stainless steel bars - Based on the UHPC grouting socket connection between ECC piers and caps, the longitudinal high-strength stainless steel bars at the bottom of the piers are connected with the high-strength stainless steel bars reserved in the cap slots through grouting sleeves, which can greatly reduce the socket depth and meet the bending moment capacity requirements of the node area under axial and horizontal loads in high-intensity areas, effectively ensuring good seismic resistance and durability of the node area, and realizing efficient and high-quality construction of prefabricated buildings and bridge structures in marine and other corrosive environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic elevation view of the present invention;

[0034] Figure 2 The present invention Figure 1 AA cross-sectional diagram of ;

[0035] Figure 3 The present invention Figure 1 BB cross-section diagram;

[0036] Figure 4 The present invention Figure 1 Schematic diagram of CC cross section;

[0037] Figure 5 Schematic diagram of the processing of prefabricated pier columns of the present invention, wherein: (a) is a schematic diagram of the binding of the steel bar skeleton; (b) is a schematic diagram of the connection between the longitudinal reinforcement of the pier column and the stainless steel reinforcement; (c) is a diagram of the placement of the pre-buried grouting sleeve; (d) is an overall diagram of the prefabricated concrete pier column;

[0038] Figure 6 Schematic diagram of the concrete foundation processing of the present invention, wherein: (a) is a schematic diagram of the steel bar skeleton binding; (b) is a schematic diagram of the placement of the reserved high-strength stainless steel bars; (c) is an overall diagram of the concrete foundation;

[0039] Figure 7The present invention is a three-dimensional schematic diagram of a prefabricated pier column-foundation, wherein: (a) is a prefabricated concrete pier column; (b) is a concrete foundation; (c) is a schematic diagram of the socket and spigot assembly of the longitudinal stainless steel bars of the pier body; (d) is a schematic diagram of grouting into the pre-buried grouting sleeve through the pre-buried grouting pipe; (e) is a schematic diagram of grouting in the socket gap; and (f) is an overall diagram of the assembled pier column-foundation. DETAILED DESCRIPTION

[0040] The following is combined with Figure 1-7 The present invention is further described in detail with specific implementations to facilitate a clear understanding of the present invention, but they do not constitute a limitation on the present invention.

[0041] Example 1

[0042] As attached Figure 1-4 As shown, the high-intensity zone stainless steel-ECC assembled pier-foundation node connection structure of this embodiment is composed of a precast concrete pier 1 and a concrete foundation 2, and the precast concrete pier 1 is inserted into the socket of the concrete foundation 2.

[0043] like Figure 1 As shown, the precast concrete pier column 1 includes an upper ordinary concrete pier column and a lower ECC concrete pier column, wherein the upper ordinary concrete pier column includes a pier body longitudinal ordinary steel bar 4 and a pier body ordinary stirrup 3 wrapped and cast together by ordinary concrete. The lower ECC concrete pier column includes a pier body longitudinal stainless steel bar 8, a pier body longitudinal high-strength stainless steel bar 7, a pre-embedded grouting sleeve 14, a pre-embedded grouting pipe 13, a pre-embedded grouting pipe 20 and a pier body FRP stirrup 18, which are wrapped and cast together by ECC concrete 6.

[0044] In this embodiment, Figure 1 As shown, the longitudinal stainless steel bars 8 of the pier body and the longitudinal ordinary steel bars 4 of the pier body, as well as the longitudinal high-strength stainless steel bars 7 of the pier body and the longitudinal ordinary steel bars 4 of the pier body are vertically connected together through the steel bar connector 5. The lower end of the longitudinal high-strength stainless steel bars 7 of the pier body is inserted into the pre-embedded grouting sleeve 14. The pre-embedded grouting sleeve 14 is pre-embedded in the bottom of the precast concrete pier 1, and its side wall is connected with the pre-embedded grouting pipe 13 and the pre-embedded grouting pipe 20 extending to the surface of the concrete pier 1. The pre-embedded grouting pipe 13 and the pre-embedded grouting pipe 20 are respectively connected to the bottom and the top of the pre-embedded grouting sleeve 14. The four pre-embedded grouting sleeves 14 are evenly arranged on the circumference of the cross-section of the lower ECC concrete pier, and three longitudinal stainless steel bars 8 of the pier body are arranged at intervals. As shown in FIG. Figure 4 shown.

[0045] In this embodiment, the concrete foundation 2 further includes foundation longitudinal steel bars 12, foundation stirrups 16, and foundation reserved high-strength stainless steel bars 15. The foundation stirrups 16 are arranged around the socket, penetrate the middle of the concrete foundation 2, and overlap the foundation longitudinal steel bars 12. The foundation reserved high-strength stainless steel bars 15 are located at the bottom of the socket of the concrete foundation 2, and the top thereof extends out of the socket and is correspondingly connected to the pier shaft longitudinal high-strength stainless steel bars 7 through the pre-embedded grouting sleeve 14, and the lower end thereof is anchored to the foundation longitudinal steel bars 12.

[0046] In addition, in this embodiment, high-strength concrete UHPC11 is poured between the inner wall of the socket of the concrete foundation 2 and the bottom side wall of the prefabricated pier 1.

[0047] In this embodiment, the specific performance parameters of each component and material are as follows: the length of the reserved high-strength stainless steel bar 15 for the foundation inserted into the reserved grouting sleeve 14 is not less than 5 times the diameter of the reserved high-strength stainless steel bar 15 for the foundation. The diameter of the embedded grouting sleeve 14 is not less than 2-3 times the diameter of the longitudinal high-strength stainless steel bar 7 of the pier body. The lengths of the longitudinal common steel bars 4 of the pier body, the longitudinal stainless steel bars 8 of the pier body, and the longitudinal high-strength stainless steel bars 7 of the pier body inserted into the steel bar connector 5 are not less than 3 times the diameter of the longitudinal stainless steel bars 8 of the pier body. The thickness of the steel bar connector 5 is not less than 2 mm. The number of the reserved high-strength stainless steel bars 15 for the foundation is 1 / 2-1 / 4 times the number of the longitudinal common steel bars 4 of the pier body. The socket depth of the precast concrete pier column 1 is not less than 0.6 times the diameter of the precast concrete pier column 1. The inner diameter of the embedded grouting sleeve 14 is 20-40 mm larger than the longitudinal high-strength stainless steel bar 7 of the pier body, and the thickness is not less than 2 mm. The inner diameter of the pre-buried grouting pipe 13 and the pre-buried grouting pipe 20 is 20-40 mm, and the wall thickness is not less than 0.5 mm. The compressive strength of the high-strength concrete UHPC11 is not less than 120 MPa, and the tensile strength is not less than 10 MPa.

[0048] Example 2

[0049] In this embodiment, a 20 mm thick mortar layer 17 is provided between the bottom surface of the precast concrete pier column 1 and the bottom surface of the socket of the concrete foundation 2. Other structures and connection methods are the same as those in Embodiment 1 and will not be described in detail here.

[0050] Example 3

[0051] The specific construction method of the high-intensity stainless steel-ECC assembled pier column-foundation node connection structure of the above-mentioned embodiment 2 includes the following steps:

[0052] S1, such as Figure 5As shown, the pier body longitudinal common steel bars 4 and the pier body common stirrups 3 are tied in the factory. After the pier body longitudinal common steel bars 4 and the pier body common stirrups 3 are tied, a steel mesh frame is formed, the formwork is supported, ordinary concrete is poured, the specimen is cured, the formwork is removed, and the production of the upper part of the pier column is completed. Subsequently, the steel bar connector 5 is installed at the end of the reserved pier body longitudinal common steel bars 4, and the pier body longitudinal stainless steel bars 8 and the pier body longitudinal high-strength stainless steel bars 7 are connected to the pier body longitudinal common steel bars 4 through the steel bar connector 5, and then the pier body FRP stirrups 18, the pre-embedded grouting sleeves 14, the pre-embedded grouting pipes 13 and the pre-embedded grouting pipes 20 are tied to form a steel mesh frame for the lower part of the pier column, the formwork is supported, the ECC concrete is poured, the specimen is cured, the formwork is removed, and the production of the precast concrete pier column 1 is completed.

[0053] S2, such as Figure 6 As shown, the foundation longitudinal steel bars 12 and foundation stirrups 16 of the concrete foundation 2 are tied on site, sockets for the precast concrete pier 1 are reserved, the foundation reserved high-strength stainless steel bars 15 are reserved and accurately positioned, and finally the formwork is supported and concrete is poured to complete the production of the precast foundation 2.

[0054] S3. The precast concrete pier 1 is transported to the construction site, a 10-30 mm thick mortar layer 17 is laid on the bottom surface of the socket of the concrete foundation 2, and the high-strength stainless steel bars 15 reserved for the foundation extending out of the socket of the concrete foundation 2 are inserted into the embedded grouting sleeve 14 of the precast concrete pier 1. The horizontality and verticality of the precast concrete pier 1 are adjusted to complete the placement of the precast concrete pier 1.

[0055] S4. Mix high-strength concrete UHPC11 on site, use high-pressure grouting equipment to fill the pre-buried grouting pipe 13 with high-strength concrete UHPC11, and use grouting method to pour high-strength concrete UHPC11 into the grouting sleeve 14 through the pre-buried grouting pipe 13 until the high-strength concrete UHPC11 overflows from the pre-buried grouting outlet 10, ensuring that the high-strength concrete UHPC11 in the grouting sleeve 14 is full. Pour high-strength concrete UHPC11 between the bottom side wall of the precast concrete pier 1 and the inner wall of the socket of the concrete foundation 2, so that the precast concrete pier 1 and the concrete foundation 2 are connected as a whole, completing the assembly of the precast concrete pier 1 and the concrete foundation 2. See Figure 7 .

[0056] The above is only a preferred embodiment of the present invention, and does not impose any formal limitation on the structure of the present invention. The layout type and the number of uses of the present invention are not limited to this example, and can be optimized and selected according to the actual project. Any modification, equivalent change and decoration of the above embodiment based on the technical principle of the present invention that does not deviate from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A stainless steel-ECC assembled pier-foundation node connection structure in a high-intensity area, comprising a precast concrete pier (1) and a concrete foundation (2), wherein the precast concrete pier (1) is inserted into a socket of the concrete foundation (2), and is characterized in that: The precast concrete pier column (1) comprises an upper ordinary concrete pier column and a lower ECC concrete pier column, wherein the upper ordinary concrete pier column comprises a pier body longitudinal ordinary steel bar (4) and a pier body ordinary stirrup (3) which are cast together by wrapping ordinary concrete; The lower ECC concrete pier column comprises a pier body longitudinal stainless steel bar (8) cast together with ECC concrete (6), a pier body longitudinal high-strength stainless steel bar (7), a pre-buried grouting sleeve (14), a pre-buried grouting pipe (13), a pre-buried grouting pipe (20) and a pier body FRP stirrup (18); The longitudinal stainless steel bars (8) of the pier body and the longitudinal ordinary steel bars (4) of the pier body, and the longitudinal high-strength stainless steel bars (7) of the pier body and the longitudinal ordinary steel bars (4) of the pier body are vertically connected together through steel bar connectors (5); the lower ends of the longitudinal high-strength stainless steel bars (7) of the pier body are inserted into the pre-embedded grouting sleeves (14); the pre-embedded grouting sleeves (14) are pre-embedded in the bottom of the precast concrete pier column (1), and the side walls thereof are connected with the pre-embedded grouting pipes (13) and the pre-embedded grouting outlet pipes (20) extending out of the surface of the concrete pier column (1); The concrete foundation (2) further comprises foundation longitudinal steel bars (12), foundation stirrups (16) and foundation reserved high-strength stainless steel bars (15). The foundation stirrups (16) are arranged around the socket, penetrate the middle of the concrete foundation (2) and overlap the foundation longitudinal steel bars (12). The foundation reserved high-strength stainless steel bars (15) are located at the bottom of the socket of the concrete foundation (2), the top of which protrudes out of the socket and is correspondingly connected to the pier shaft longitudinal high-strength stainless steel bars (7) through the pre-buried grouting sleeve (14), and the lower end of which is anchored to the foundation longitudinal steel bars (12). High-strength concrete UHPC (11) is poured between the inner wall of the socket of the concrete foundation (2) and the bottom side wall of the prefabricated pier (1).

2. The high-intensity stainless steel-ECC assembled pier-foundation node connection structure according to claim 1 is characterized by: The length of the foundation reserved high-strength stainless steel bar (15) inserted into the reserved grouting sleeve (14) is not less than 5 times the diameter of the foundation reserved high-strength stainless steel bar (15); the diameter of the pre-buried grouting sleeve (14) is not less than 2-3 times the diameter of the longitudinal high-strength stainless steel bar (7) of the pier body.

3. The high-intensity stainless steel-ECC assembled pier-foundation node connection structure according to claim 1 is characterized by: The lengths of the pier shaft longitudinal common steel bars (4), the pier shaft longitudinal stainless steel bars (8) and the pier shaft longitudinal high-strength stainless steel bars (7) inserted into the steel bar connector (5) are not less than three times the diameter of the pier shaft longitudinal stainless steel bars (8).

4. The high-intensity stainless steel-ECC assembled pier-foundation node connection structure according to claim 1 is characterized by: The thickness of the steel bar connector (5) is not less than 2 mm.

5. The high-intensity stainless steel-ECC assembled pier-foundation node connection structure according to claim 1 is characterized by: The high-strength concrete UHPC (11) has a compressive strength of not less than 120 MPa and a tensile strength of not less than 10 MPa.

6. The high-intensity stainless steel-ECC assembled pier-foundation node connection structure according to claim 1 is characterized by: The number of high-strength stainless steel bars (15) reserved in the foundation is 1 / 2-1 / 4 times the number of common steel bars (4) in the longitudinal direction of the pier body; the socket depth of the precast concrete pier column (1) is not less than 0.6 times the diameter of the precast concrete pier column (1).

7. The high-intensity stainless steel-ECC assembled pier-foundation node connection structure according to claim 1 is characterized by: The inner diameter of the pre-buried grouting sleeve (14) is 20-40 mm larger than the longitudinal high-strength stainless steel rib (7) of the pier body, and the thickness is not less than 2 mm; the inner diameter of the pre-buried grouting pipe (13) and the pre-buried grouting outlet pipe (20) is 20-40 mm, and the wall thickness is not less than 0.5 mm.

8. The high-intensity stainless steel-ECC assembled pier-foundation node connection structure according to claim 7 is characterized by: The pre-buried grouting pipe (13) and the pre-buried grouting outlet pipe (20) are respectively connected to the bottom and the top of the pre-buried grouting sleeve (14); the pre-buried grouting sleeve (14) is evenly arranged on the circumference of the cross section of the lower ECC concrete pier column, and a plurality of longitudinal stainless steel bars (8) of the pier body are arranged at intervals.

9. The high-intensity stainless steel-ECC assembled pier-foundation node connection structure according to claim 1 is characterized by: A 10-30 mm thick mortar layer (17) is provided between the bottom surface of the precast concrete pier column (1) and the bottom surface of the socket of the concrete foundation (2).

10. The construction method of the high-intensity zone stainless steel-ECC assembled pier-foundation node connection structure according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, tying the pier body longitudinal common steel bars (4) and the pier body common stirrups (3) in the factory, forming a steel mesh after the pier body longitudinal common steel bars (4) and the pier body common stirrups (3) are tied, supporting the formwork, pouring common concrete, curing the specimen, removing the formwork, and completing the production of the upper part of the pier column; then installing the steel bar connector (5) at the end of the reserved pier body longitudinal common steel bars (4), connecting the pier body longitudinal stainless steel bars (8) and the pier body longitudinal high-strength stainless steel bars (7) with the pier body longitudinal common steel bars (4) through the steel bar connector (5), and then tying the pier body FRP stirrups (18), pre-embedded grouting sleeves (14), pre-embedded grouting pipes (13) and pre-embedded grouting pipes (20) to form a steel mesh at the lower part of the pier column, supporting the formwork, pouring ECC concrete, curing the specimen, removing the formwork, and completing the production of the precast concrete pier column (1); S2, tying the foundation longitudinal steel bars (12) and foundation stirrups (16) of the concrete foundation (2) on site, reserving sockets for placing the precast concrete piers (1), reserving and accurately positioning the foundation reserved high-strength stainless steel bars (15), and finally supporting the formwork and pouring concrete to complete the production of the precast foundation (2); S3, transport the precast concrete pier (1) to the construction site, lay a 10-30 mm thick grouting layer (17) on the bottom surface of the socket of the concrete foundation (2), insert the foundation reserved high-strength stainless steel reinforcement (15) extending out of the socket of the concrete foundation (2) into the pre-buried grouting sleeve (14) of the precast concrete pier (1), adjust the horizontality and verticality of the precast concrete pier (1), and complete the placement of the precast concrete pier (1); S4, mixing high-strength concrete UHPC (11) on site, using a high-pressure grouting device to fill the pre-buried grouting pipe (13) with the high-strength concrete UHPC (11), using a grouting method to pour the high-strength concrete UHPC (11) into the grouting sleeve (14) through the pre-buried grouting pipe (13), until the high-strength concrete UHPC (11) overflows from the pre-buried grouting outlet (10), ensuring that the high-strength concrete UHPC (11) in the grouting sleeve (14) is full; pouring high-strength concrete UHPC (11) between the bottom side wall of the precast concrete pier (1) and the inner wall of the socket of the concrete foundation (2), so that the precast concrete pier (1) and the concrete foundation (2) are connected into a whole, completing the assembly work of the precast concrete pier (1) and the concrete foundation (2).

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