FRP composite reinforced recycled concrete prefabricated assembly pier-foundation socket joint and construction method

Abstract

The present invention relates to an FRP composite reinforced recycled concrete prefabricated assembly pier column-foundation socket node and construction method, and belongs to the field of structural engineering technology. It includes a prefabricated recycled concrete pier column and a recycled concrete foundation, which are connected by a pre-buried horizontal resistance device, a pre-buried metal bellows and a UHPC grouting socket combination in the recycled concrete foundation to ensure the connection reliability and seismic safety of the assembled node. The prefabricated recycled concrete pier column is composed of longitudinal FRP composite bars and stirrups, and the recycled concrete foundation is composed of a horizontal resistance device, a pre-buried metal bellows, a reserved grouting pressure pipe, a reserved slot, a foundation longitudinal steel bar and a foundation stirrup. The longitudinal FRP composite bars of the pier column and the metal bellows are connected by grouting to resist the pull-out force in the node area, while the horizontal force is borne jointly by the concrete and the horizontal resistance device. The horizontal resistance device will bear most of the horizontal forces around the foundation socket slot, reducing the compressive damage of the foundation concrete.

Description

Technical Field

[0001] The present invention relates to a prefabricated pier column-foundation structure, in particular to an FRP composite reinforced recycled concrete prefabricated pier column-foundation socket joint and a construction method, belonging to the technical field of structural engineering. Background Art

[0002] As a key infrastructure project, bridges face enormous construction demand. Traditional bridge construction relies on cast-in-place methods, which pose challenges such as long construction periods, significant environmental pollution, and difficult-to-control construction quality. The introduction of prefabrication technology can address these issues, reduce environmental pollution, and ensure component quality. Prefabrication utilizes FRP composite reinforcement and UHPC, offering high strength and durability, making it particularly suitable for bridge construction in coastal areas, lakes and swamps, alpine regions, urban roads, and areas with stringent environmental protection requirements.

[0003] However, my country is located between the Pacific Rim and the Eurasian Seismic Belt, with high seismic activity, which has a significant impact on transportation bridges. Structural nodes are the hubs of various components and are key areas for design optimization. The prefabricated structural node connection structure of bridges is the weakest part, and a pier-foundation node connection structure and construction process suitable for strong earthquake zones should be proposed to meet the seismic performance of actual bridge projects in strong earthquake zones. The seismic performance of the currently proposed prefabricated structural node structure of the lower part of the bridge is still relatively weak and can no longer serve the future transportation road industry well, especially for structures located in strong earthquake zones. There is a great demand for prefabricated structural node connections with excellent "safety" and "seismic performance" to serve strong earthquake zones. The demand for prefabricated structural node connection structures of bridges in strong earthquake zones is imminent.

[0004] In the prefabricated pier column node connection technology, the socket connection has the advantages of simple connection, strong adaptability and reduced on-site construction. However, the traditional pier column-foundation socket node structure connection usually requires a larger socket depth to meet the seismic requirements. For example, CN107869150A discloses a prefabricated assembly column and reinforced concrete foundation connection structure and construction method, and CN110284516A discloses a lightweight prefabricated assembly concrete slab column foundation and construction method. These results in a large range of the pedestal longitudinal reinforcement being interrupted, causing its bending resistance to decrease. At the same time, in order to meet the pedestal's shear resistance and high seismic resistance zone performance, the overall size of the pedestal is made larger, which is not conducive to structural economy.

[0005] Therefore, it is urgent to propose a new type of assembled pier-foundation socket-type node structure to solve the above problems. Summary of the Invention

[0006] In response to the above-mentioned defects of the above-mentioned prior art, the present invention proposes an FRP composite reinforced recycled concrete prefabricated assembly pier-foundation socket node and construction method, which can well meet the seismic performance of the connection node, and has the advantages of simple construction process, green solid waste recycling, corrosion resistance, low socket depth and high ductility, and provides a new solution for the design of prefabricated pier-foundation node connections in the field of bridge engineering.

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

[0008] The FRP composite reinforced recycled concrete prefabricated assembly pier-foundation socket node consists of a prefabricated recycled concrete pier and a recycled concrete foundation. The prefabricated recycled concrete pier is inserted into the foundation hole groove of the recycled concrete foundation. The prefabricated recycled concrete pier includes longitudinal FPR composite reinforcement of the pier body and pier body stirrups; the recycled concrete foundation includes pre-buried metal bellows, pre-buried grouting high-pressure pipes and horizontal resistance devices; the longitudinal FPR composite reinforcement of the pier body is pre-buried in the inner periphery of the prefabricated recycled concrete pier, and the part of the bottom extending from the prefabricated pier is inserted into the interior of the pre-buried metal bellows, and high-strength concrete UHPC is poured into the interior of the pre-buried metal bellows; the pre-buried metal bellows is pre-buried in the bottom of the recycled concrete foundation socket, and the top surface of the metal bellows slurry outlet at its upper end is flush with the bottom surface of the recycled concrete foundation socket; the side wall of the pre-buried metal bellows is connected to the pre-buried grouting high-pressure pipe extending to the upper surface of the recycled concrete foundation; the horizontal resistance device includes an upper T-shaped longitudinal steel beam, a lower cross-shaped longitudinal steel beam, The horizontal force-resisting device is embedded in the periphery of the reserved socket of the recycled concrete foundation, located below the foundation longitudinal reinforcement and stirrups inside the recycled concrete foundation, and welded to the foundation longitudinal reinforcement and stirrups. The load-bearing steel plate is welded to one end of the T-shaped longitudinal steel beam and the cross-shaped longitudinal steel beam, and the load-bearing steel plate extends out of the periphery of the recycled concrete foundation socket and is confined between the four sides of the bottom of the precast recycled concrete pier and the periphery of the foundation socket. A load-bearing steel plate support is welded between the back of the load-bearing steel plate and the T-shaped longitudinal steel beam. Anchor steel plates are welded to the other ends of the T-shaped longitudinal steel beam and the cross-shaped longitudinal steel beam. Multiple load-bearing steel plates and multiple anchor steel plates are welded together through horizontal connecting steel plates and vertical connecting steel plates. The central reinforcing connecting steel plate is provided with a T-shaped hole and a cross-shaped hole. The T-shaped longitudinal steel beam and the cross-shaped longitudinal steel beam pass through the T-shaped hole and the cross-shaped hole respectively and are welded to the middle of the reinforcing connecting steel plate to form a whole. Horizontal connecting steel plates are welded between the central reinforcing connecting steel plates.

[0009] Furthermore, the metal bellows slurry outlet is a hole cut on one side of the upper end of the embedded metal bellows, with a height of not less than 40 mm and a width of not less than 40 mm. Steel plates are welded on the three edges of the incision, and the length of the steel plates is not less than 90 mm, thereby forming the metal bellows slurry outlet; the far end of the metal bellows slurry outlet is facing the direction of the gap between the prefabricated recycled concrete pier and the recycled concrete foundation.

[0010] Furthermore, the length of the pier longitudinal FPR composite reinforcement inserted into the embedded metal bellows is not less than 10 times the diameter of the pier longitudinal FPR composite reinforcement; the diameter of the embedded metal bellows is not less than 2-3 times the diameter of the pier longitudinal FPR composite reinforcement; the horizontal distance of the horizontal resistance device buried horizontally in the recycled concrete foundation is not less than 3-6 times the socket depth.

[0011] Furthermore, the horizontal distance between the load-bearing steel plate and the four side surfaces of the bottom of the precast recycled concrete pier and the four side surfaces of the socket is not less than 20 mm, and the vertical distance between the load-bearing steel plate and the bottom surface of the precast recycled concrete pier is not less than 20 mm, and the horizontal resistance device located inside the recycled concrete foundation is fixed to the foundation longitudinal steel bars and foundation stirrups by welding.

[0012] 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.

[0013] Furthermore, the number of the longitudinal FPR composite bars extending out of the prefabricated recycled concrete pier column is 1 / 2-1 / 4 times the total number of the longitudinal FPR composite bars in the prefabricated recycled concrete pier column; and the socket depth of the prefabricated recycled concrete pier column is not less than 0.6 times the side length of the prefabricated recycled concrete pier column.

[0014] Furthermore, the inner diameter of the embedded metal corrugated pipe is 20-40mm larger than the longitudinal FPR composite reinforcement of the pier body, or the larger value of the inner diameter of 60mm, and the thickness is not less than 2mm; the inner diameter of the embedded grouting high-pressure pipe is 20-40mm, and the wall thickness is not less than 0.5mm.

[0015] Furthermore, a 10-30 mm mortar layer is provided between the bottom surface of the prefabricated recycled concrete pier column and the bottom surface of the recycled concrete foundation socket.

[0016] Furthermore, the foundation stirrups inside the recycled concrete foundation are arranged around the sockets, pass through the middle of the recycled concrete foundation and overlap with the foundation longitudinal reinforcement.

[0017] The construction method of the FRP composite reinforced recycled concrete prefabricated assembly pier column-foundation socket node comprises the following steps:

[0018] S1. Tie the longitudinal FPR composite bars and stirrups of the pier body in the factory, and reserve the longitudinal FPR composite bars of the pier body for extending out of the precast recycled concrete pier column and inserting into the pre-embedded metal corrugated pipe of the foundation. After the longitudinal FPR composite bars and stirrups of the pier body are tied, a steel grid is formed, the formwork is supported, the recycled concrete is poured, the test pieces are cured, and the formwork is removed to complete the production of the precast recycled concrete pier column.

[0019] S2. Process the T-shaped longitudinal steel beam, cross-shaped longitudinal steel beam, load-bearing steel plate, horizontal connecting steel plate, vertical connecting steel plate, anchoring steel plate, load-bearing steel plate support, and middle reinforcing connecting steel plate components of the horizontal force-resisting device in the factory; weld the load-bearing steel plate and anchoring steel plate to one end of the T-shaped longitudinal steel beam and the cross-shaped longitudinal steel beam, respectively; connect the T-shaped longitudinal steel beam and the cross-shaped longitudinal steel beam together by using the middle reinforcing connecting steel plate and weld them; weld the horizontal connecting steel plate and the vertical connecting steel plate to the load-bearing steel plate, the anchoring steel plate, and the middle reinforcing connecting steel plate; and obliquely weld the load-bearing steel plate support to the upper part of the T-shaped longitudinal steel beam and the side of the load-bearing steel plate to form an integral load-bearing steel skeleton, thereby completing the production of the horizontal force-resisting device;

[0020] S3. Tie the longitudinal reinforcement and stirrups of the recycled concrete foundation on site, reserve a socket for the prefabricated recycled concrete pier, and horizontally place the horizontal resistance devices processed in the factory on the four sides of the socket. The horizontal resistance devices inside the recycled concrete foundation are connected to the longitudinal reinforcement and stirrups of the foundation by welding to fix them, so that each load-bearing steel plate is parallel to the four side surfaces of the socket, and pre-embed a metal bellows on the bottom of the socket. Pre-embed a grouting high-pressure pipe at the bottom edge of each pre-embedded metal bellows and extend it to the top surface of the recycled concrete foundation to serve as a grouting channel. The upper end of the metal bellows grouting outlet at the upper end of the pre-embedded metal bellows is parallel to the bottom surface of the recycled concrete foundation socket, and the pre-embedded grouting high-pressure pipe connected to the lower end of the pre-embedded metal bellows and the metal bellows grouting outlet welded at the lower end are both vertically limited to the four sides of the socket. Support the formwork, pour the recycled concrete, maintain the components, remove the formwork, and complete the production of the recycled concrete foundation;

[0021] S4. Transport the precast recycled concrete pier to the construction site, lay a 10-30mm thick mortar layer on the bottom surface of the recycled concrete foundation socket, insert the load-bearing steel plates of the four sides of the bottom of the precast recycled concrete pier parallel to the horizontal resistance device on all sides into the socket, extend the longitudinal FPR composite reinforcement of the pier body of the precast recycled concrete pier vertically into the embedded metal corrugated pipe, adjust the horizontality and verticality of the precast recycled concrete pier, and complete the placement of the precast recycled concrete pier.

[0022] S5. Mix high-strength concrete UHPC on site, use a grouting device to fill the pre-buried grouting high-pressure pipe with high-strength concrete UHPC, use the grouting method to pour high-strength concrete UHPC through the top of the pre-buried grouting high-pressure pipe, wait for the high-strength concrete UHPC to overflow from the slurry outlet of each metal corrugated pipe, ensure that the corrugated pipe is fully grouted, and pour high-strength concrete UHPC between the four sides of the bottom of the precast recycled concrete pier column and the four sides of the recycled concrete foundation socket, so that the precast recycled concrete pier column and the recycled concrete foundation are connected into a whole, completing the assembly work of the precast recycled concrete pier column and the recycled concrete foundation.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention utilizes the technology of prefabricated factories to process prefabricated piers. The connection nodes between the prefabricated recycled concrete piers and the recycled concrete foundations utilize a socket-and-socket connection structure combined with a horizontal resistance device. The prefabricated piers and foundations are entirely constructed of recycled concrete components. Environmentally friendly technologies and clean energy are employed to reduce pollution emissions, protect natural resources, and restore and maintain ecological balance. While ensuring both construction and component quality, the present invention offers advantages such as a simple construction method, a simple node structure, and a low socket-and-socket depth. Prefabrication and assembly can save on-site workload and time, reduce labor costs, transportation costs, and reduce environmental pollution. The FRP composite reinforcement of the prefabricated piers can improve durability and corrosion resistance, increase service life, and reduce maintenance costs. Recycled concrete is a solid waste, and recycling can enhance environmental protection. This fully utilizes the environmentally friendly, energy-saving, and renewable characteristics of green building materials, promoting their development and application.

[0025] 2. The majority of the horizontal force resistance device's skeleton is placed within the foundation. The skeleton within the foundation strengthens the connectivity between the recycled concrete surrounding the socket and the recycled concrete at the distal end of the foundation, forming a holistic structure that resists the expansion of diagonal cracks extending to the top surface of the foundation due to stress at the bottom of the socket. This also enhances the horizontal resistance of the connection node. The skeleton located in the socket area improves the anchoring capacity of the high-strength concrete (UHPC) between the pier and the foundation. The horizontal force at the connection node is shared by the concrete and the horizontal force resistance device. The horizontal force resistance device bears most of the horizontal force around the foundation socket, reducing compressive damage to the cap concrete. The plastic hinge area is initially generated in the pier above the connection node. This novel device creates a superior mechanism for pier-foundation coordination, further effectively enhancing the seismic performance of the pier-foundation connection node.

[0026] 3. The grouting connection between the longitudinal FRP composite reinforcement of the pier column and the metal bellows anchored to the foundation can resist the pull-out force in the node area. The number of FRP composite reinforcements of the pier body extending out of the bottom cross-section of the pier column accounts for 1 / 3-2 / 3 of the total. At the same time, the use of UHPC grouting connection greatly reduces the number of metal bellows and grouting pressure pipes in the foundation and the anchorage length of the FRP composite reinforcement while ensuring sufficient connection strength and seismic resistance requirements. This effectively reduces the difficulty and accuracy during prefabrication and assembly construction, further optimizes the structure of the connection node, reduces the reserved holes in the foundation, improves the integrity of the foundation structure, reduces the project cost, simplifies the construction process, and saves construction costs.

[0027] 4. Pre-buried corrugated pipes and pre-buried grouting pressure pipes in the foundation. The corrugated pipes can prevent the FRP composite bars of the pier body from being pulled out and damaged by the UHPC during the pulling process, and thus strengthen the connection node structure. In order to ensure a reliable connection between the pier column FRP composite bars and the foundation, high-strength concrete UHPC is poured into the pre-buried corrugated pipes through the pre-buried grouting pressure pipes. The overflow port at the top of the corrugated pipe is used to ensure that the UHPC filling in the corrugated pipe is dense and complete, ensuring the filling quality of the UHPC, making the pier column-foundation connection an integral whole, resisting the pulling force under earthquake action, and improving seismic safety and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic elevation view of the present invention;

[0029] Figure 2 This invention Figure 1 AA cross-sectional diagram of ;

[0030] Figure 3 This invention Figure 1 BB cross-section diagram;

[0031] Figure 4 Schematic diagram of the horizontal force resisting device and its components of the present invention, wherein: (a) is a schematic diagram of the horizontal force resisting device, (b) is a cross-sectional diagram of a cross-shaped longitudinal steel beam, (c) is a cross-sectional diagram of a T-shaped longitudinal steel beam, and (d) is a cross-sectional diagram of a central reinforcement connecting plate;

[0032] Figure 5 Schematic diagram of the processing of prefabricated recycled concrete columns of the present invention, wherein: (a) is a schematic diagram of steel bar skeleton binding, (b) is an overall diagram of the prefabricated recycled concrete pier column;

[0033] Figure 6 Schematic diagram of recycled concrete foundation processing according to the present invention, wherein: (a) is a schematic diagram of steel bar skeleton binding, (b) is a schematic diagram of horizontal resistance device, (c) is a diagram of placement of pre-buried metal bellows and grouting pressure pipe, (d) is a schematic diagram of placement of horizontal resistance device, and (e) is an overall diagram of recycled concrete foundation;

[0034] Figure 7 It is a three-dimensional schematic diagram of the prefabricated assembled pier column-foundation of the present invention, wherein: (a) is a prefabricated recycled concrete pier column, (b) is a recycled concrete foundation, (c) is an assembly diagram of the longitudinal FRP composite steel bar sockets of the pier body, (d) is a schematic diagram of grouting the embedded metal corrugated pipe through the grouting pressure pipe, (e) is a schematic diagram of grouting the socket gap, and (f) is an overall diagram of the assembled pier column-foundation. DETAILED DESCRIPTION

[0035] The following is combined with Figure 1-7 The present invention will be further described in detail with specific implementations to facilitate a clear understanding of the present invention, but they do not constitute a limitation to the present invention.

[0036] Example 1

[0037] As attached Figure 1-3 As shown, the FRP composite reinforced recycled concrete prefabricated assembly pier column-foundation socket joint of this embodiment is composed of a prefabricated recycled concrete pier column 1 and a recycled concrete foundation 4. The prefabricated recycled concrete pier column 1 is inserted into the foundation hole groove of the recycled concrete foundation 4. Figure 2 and Figure 5 As shown, the precast recycled concrete pier column 1 includes longitudinal FPR composite bars 2 and stirrups 3. The recycled concrete foundation 4 includes a pre-embedded metal bellows 5, a pre-embedded high-pressure grouting pipe 6, and a horizontal force resistance device 10. The longitudinal FPR composite bars 2 are pre-embedded around the interior of the precast recycled concrete pier column 1. The portion of the bar extending from the precast pier column 1 is inserted into the pre-embedded metal bellows 5, and high-strength concrete (UHPC) 7 is poured into the pre-embedded metal bellows 5. The pre-embedded metal bellows 5 is pre-embedded in the bottom of the socket of the recycled concrete foundation 4, with the top surface of the metal bellows slurry outlet 20 at its upper end flush with the bottom surface of the socket of the recycled concrete foundation 4. The side wall of the pre-embedded metal bellows 5 is connected to a pre-embedded high-pressure grouting pipe 6 that extends to the upper surface of the recycled concrete foundation 4.

[0038] In this embodiment, Figure 3-4 as well as Figure 6As shown, the horizontal force-resisting device 10 comprises an upper T-shaped longitudinal steel beam 11, a lower cross-shaped longitudinal steel beam 12, a load-bearing steel plate 13, and a central reinforcing connecting steel plate 18. The horizontal force-resisting device 10 is embedded around the reserved socket of the recycled concrete foundation 4, located below the foundation longitudinal reinforcement 8 and foundation stirrups 9 within the recycled concrete foundation 4, and welded to the foundation longitudinal reinforcement 8 and foundation stirrups 9. In this embodiment, the foundation stirrups 9 within the recycled concrete foundation 4 are arranged around the socket, passing through the middle of the recycled concrete foundation 4 and overlapping the foundation longitudinal reinforcement 8. The load-bearing steel plate 13 is welded to one end of the T-shaped longitudinal steel beam 11 and the cross-shaped longitudinal steel beam 12. The load-bearing steel plate 13 extends around the socket of the recycled concrete foundation 4 and is confined between the four sides of the bottom of the precast recycled concrete pier 1 and the four sides of the foundation socket. A load-bearing steel plate support 17 is welded between the back of the load-bearing steel plate 13 and the T-shaped longitudinal steel beam 11. Anchor plates 16 are welded to the other ends of the T-shaped longitudinal steel beams 11 and cross-shaped longitudinal steel beams 12. The multiple load-bearing steel plates 13 and the multiple anchor plates 16 are welded together via horizontal connecting steel plates 14 and vertical connecting steel plates 15. A central reinforcing connecting steel plate 18 is provided with T-shaped and cross-shaped holes. The T-shaped longitudinal steel beams 11 and cross-shaped longitudinal steel beams 12 pass through the T-shaped and cross-shaped holes, respectively, and are welded to the central portion of the reinforcing connecting steel plate 18, forming a single unit. Horizontal connecting steel plates 14 are welded between the central reinforcing connecting steel plates 18.

[0039] In this embodiment, the specific parameters of each component are as follows: The metal bellows grouting opening 20 is a cutout on one side of the upper end of the embedded metal bellows 5, with a height of 40 mm and a width of 40 mm. Steel plates with a length of 90 mm are welded to the three edges of the cutout, forming the metal bellows grouting opening 20. The distal end of the metal bellows grouting opening 20 faces the gap between the precast recycled concrete pier column 1 and the recycled concrete foundation 4. Furthermore, the length of the longitudinal FPR composite reinforcement 2 inserted into the embedded metal bellows 5 is 10 times the diameter of the longitudinal FPR composite reinforcement 2. The diameter of the embedded metal bellows 5 is 3 times the diameter of the longitudinal FPR composite reinforcement 2. The horizontal distance of the horizontal force resistance device 10 embedded in the recycled concrete foundation 4 is not less than 6 times the socket depth. In this embodiment, the number of longitudinal FPR composite reinforcement 2 extending from the precast recycled concrete pier column 1 is 1 / 2 the total number of longitudinal FPR composite reinforcement 2 within the precast recycled concrete pier column 1. The socket depth of the precast recycled concrete pier column 1 is 0.6 times the side length of the precast recycled concrete pier column 1. The inner diameter of the embedded metal corrugated pipe 5 is 20-40mm larger than the longitudinal FPR composite reinforcement 2 of the pier body, or the larger value of the inner diameter of 60mm, and the thickness is not less than 2mm. The inner diameter of the embedded grouting high-pressure pipe 6 is 20-40mm, and the wall thickness is not less than 0.5mm. In addition, if Figure 1As shown, the horizontal distance between the load-bearing steel plate 13 and the four side surfaces of the bottom of the precast recycled concrete pier 1 and the four side surfaces of the socket is 20 mm, and the vertical distance between the load-bearing steel plate 13 and the bottom surface of the precast recycled concrete pier 1 is 20 mm. The horizontal resistance device 10 located inside the recycled concrete foundation 4 is fixed to the foundation longitudinal steel bars 8 and the foundation stirrups 9 by welding.

[0040] In this embodiment, the compressive strength of the high-strength concrete UHPC7 is not less than 120 MPa, and the tensile strength is not less than 10 MPa.

[0041] Example 2

[0042] In this embodiment, a 30 mm thick mortar layer 19 is provided between the bottom surface of the prefabricated recycled concrete pier 1 and the bottom surface of the socket of the recycled concrete foundation 4 . Other structures and connection methods are the same as those in the first embodiment.

[0043] Example 3

[0044] The specific construction method of the FRP composite reinforced recycled concrete prefabricated assembly pier column-foundation socket joint in the above embodiment 2 includes the following steps:

[0045] S1. Tie the longitudinal FPR composite bars 2 of the pier body, the stirrups 3 of the pier body, and the reserved portion of the pier body longitudinal FPR composite bars 2 to be extended out of the prefabricated recycled concrete pier column 1 and inserted into the pre-embedded metal corrugated pipe 5 of the foundation 5 in the factory. After the pier body longitudinal FPR composite bars 2 and the stirrups 3 are tied, a steel mesh is formed, the formwork is supported, the recycled concrete is poured, the test pieces are cured, and the formwork is removed to complete the production of the prefabricated recycled concrete pier column 1.

[0046] S2. Process the T-shaped longitudinal steel beam 11, cross-shaped longitudinal steel beam 12, load-bearing steel plate 13, horizontal connecting steel plate 14, vertical connecting steel plate 15, anchoring steel plate 16, load-bearing steel plate support 17 and middle reinforcing connecting steel plate 18 components of the horizontal resistance device 10 in the factory, weld the load-bearing steel plate 13 and anchoring steel plate 16 to one end of the T-shaped longitudinal steel beam 11 and the cross-shaped longitudinal steel beam 12 respectively, connect the T-shaped longitudinal steel beam 11 and the cross-shaped longitudinal steel beam 12 together and weld them by using the middle reinforcing connecting steel plate 18, weld the horizontal connecting steel plate 14 and the vertical connecting steel plate 15 to the load-bearing steel plate 13, anchoring steel plate 16 and the middle reinforcing connecting steel plate 18, and obliquely weld the load-bearing steel plate support 17 to the upper part of the T-shaped longitudinal steel beam 11 and the side of the load-bearing steel plate 13 to form an integral load-bearing steel skeleton, thereby completing the production of the horizontal resistance device 10.

[0047] S3. Tie the foundation longitudinal steel bars 8 and foundation stirrups 9 of the recycled concrete foundation 4 on site, reserve a socket for placing the prefabricated recycled concrete pier 1, and horizontal resistance devices 10 processed and manufactured in the factory are placed horizontally on the four sides of the socket. The horizontal resistance device 10 inside the recycled concrete foundation 4 is fixed to the foundation longitudinal steel bars 8 and foundation stirrups 9 by welding, so that each load-bearing steel plate 13 is parallel to the four side surfaces of the socket, and pre-embed a metal bellows 5 on the bottom surface of the socket. A pre-embedded grouting high-pressure pipe 6 is embedded at the bottom edge of each pre-embedded metal bellows 5 and extends to the top surface of the recycled concrete foundation 4 as a grouting channel. The upper end of the metal bellows slurry outlet 20 at the upper end of the pre-embedded metal bellows 5 is parallel to the bottom surface of the socket of the recycled concrete foundation 4. The pre-embedded grouting high-pressure pipe 6 connected to the lower end of the pre-embedded metal bellows 5 and the metal bellows slurry outlet 20 welded at the lower end are both vertically limited to the four sides of the socket. Support the formwork, pour recycled concrete, maintain the components, remove the formwork, and complete the production of the recycled concrete foundation 4.

[0048] S4. Transport the prefabricated recycled concrete pier 1 to the construction site, lay a 10-30 mm thick mortar layer 19 on the bottom surface of the socket of the recycled concrete foundation 4, insert the load-bearing steel plates 13 of the four sides of the bottom of the prefabricated recycled concrete pier 1 through the surrounding horizontal resistance devices 10 into the socket, extend the longitudinal FPR composite reinforcement 2 of the pier body of the prefabricated recycled concrete pier 1 vertically into the embedded metal corrugated pipe 5, adjust the horizontality and verticality of the prefabricated recycled concrete pier 1, and complete the placement of the prefabricated recycled concrete pier 1.

[0049] S5. Mix high-strength concrete UHPC7 on site, use a grouting device to fill the pre-buried grouting high-pressure pipe 6 with high-strength concrete UHPC7, use a grouting method to pour high-strength concrete UHPC7 through the top of the pre-buried grouting high-pressure pipe 6, wait for the high-strength concrete UHPC7 to overflow from the slurry outlets 20 of each metal corrugated pipe, ensure that the corrugated pipe is fully grouted, and pour high-strength concrete UHPC7 between the four sides of the bottom of the prefabricated recycled concrete pier column 1 and the four sides of the socket of the recycled concrete foundation 4, so that the prefabricated recycled concrete pier column 1 and the recycled concrete foundation 4 are connected into a whole, completing the assembly of the prefabricated recycled concrete pier column 1 and the recycled concrete foundation 4.

[0050] The above is merely a preferred embodiment of the present invention and does not constitute any formal limitation on the structure of the present invention. The layout and number of the present invention are not limited to this example and can be optimized according to actual engineering practices. Any modifications, equivalent changes, and decorations to the above embodiment based on the technical principles of the present invention that do not depart 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. An FRP composite reinforced recycled concrete prefabricated assembly pier column-foundation socket joint, comprising a prefabricated recycled concrete pier column (1) and a recycled concrete foundation (4), wherein the prefabricated recycled concrete pier column (1) is inserted into a foundation hole groove of the recycled concrete foundation (4), and is characterized in that: The prefabricated recycled concrete pier column (1) includes longitudinal FPR composite reinforcement (2) and pier stirrups (3); the recycled concrete foundation (4) includes a pre-buried metal corrugated pipe (5), a pre-buried grouting high-pressure pipe (6), and a horizontal resistance device (10); The longitudinal FPR composite reinforcement (2) of the pier body is pre-embedded around the interior of the prefabricated recycled concrete pier column (1), and the portion of the bottom extending out of the prefabricated recycled concrete pier column (1) is inserted into the interior of the pre-embedded metal corrugated pipe (5), and high-strength concrete UHPC (7) is poured into the interior of the pre-embedded metal corrugated pipe (5); The pre-buried metal bellows (5) is pre-buried in the bottom of the socket of the recycled concrete foundation (4), and the top surface of the metal bellows slurry outlet (20) at its upper end is flush with the bottom surface of the socket of the recycled concrete foundation (4); the side wall of the pre-buried metal bellows (5) is connected to a pre-buried grouting high-pressure pipe (6) extending to the upper surface of the recycled concrete foundation (4); The horizontal force-resisting device (10) comprises an upper T-shaped longitudinal steel beam (11), a lower cross-shaped longitudinal steel beam (12), a stress-bearing steel plate (13) and a middle reinforced connecting steel plate (18); the horizontal force-resisting device (10) is embedded in the four sides of the reserved socket of the recycled concrete foundation (4), is located below the foundation longitudinal steel bars (8) and foundation stirrups (9) inside the recycled concrete foundation (4), and is welded to the foundation longitudinal steel bars (8) and foundation stirrups (9); the stress-bearing steel plate (13) is welded to one end of the T-shaped longitudinal steel beam (11) and the cross-shaped longitudinal steel beam (12), and the stress-bearing steel plate (13) extends out of the four sides of the socket of the recycled concrete foundation (4) and is limited between the four sides of the bottom of the prefabricated recycled concrete pier (1) and the four sides of the foundation socket; a stress-bearing steel plate support (17) is welded between the back of the stress-bearing steel plate (13) and the T-shaped longitudinal steel beam (11); Anchoring steel plates (16) are welded to the other ends of the T-shaped longitudinal steel beam (11) and the cross-shaped longitudinal steel beam (12); the plurality of load-bearing steel plates (13) and the plurality of anchoring steel plates (16) are welded together via horizontal connecting steel plates (14) and vertical connecting steel plates (15); The middle reinforcing connecting steel plate (18) is provided with a T-shaped hole and a cross-shaped hole, the T-shaped longitudinal steel beam (11) and the cross-shaped longitudinal steel beam (12) respectively pass through the T-shaped hole and the cross-shaped hole and are welded to the middle of the reinforcing connecting steel plate (18) to form a whole, and horizontal connecting steel plates (14) are welded between the middle reinforcing connecting steel plates (18).

2. The FRP composite reinforced recycled concrete prefabricated assembly pier column-foundation socket joint according to claim 1, characterized in that: The metal bellows slurry outlet (20) is a hole cut on one side of the upper end of the embedded metal bellows (5), with a height of not less than 40 mm and a width of not less than 40 mm. Steel plates are welded to the three edges of the cut, and the length of the steel plates is not less than 90 mm, thereby forming the metal bellows slurry outlet (20); the distal end of the metal bellows slurry outlet (20) faces the direction of the gap between the prefabricated recycled concrete pier (1) and the recycled concrete foundation (4).

3. The FRP composite reinforced recycled concrete prefabricated assembly pier column-foundation socket joint according to claim 1, characterized in that: The length of the pier body longitudinal FPR composite reinforcement (2) inserted into the pre-buried metal corrugated pipe (5) is not less than 10 times the diameter of the pier body longitudinal FPR composite reinforcement (2); the diameter of the pre-buried metal corrugated pipe (5) is not less than 2-3 times the diameter of the pier body longitudinal FPR composite reinforcement (2); and the horizontal distance of the horizontal resistance device (10) horizontally embedded in the recycled concrete foundation (4) is not less than 3-6 times the socket depth.

4. The FRP composite reinforced recycled concrete prefabricated assembly pier column-foundation socket joint according to claim 1, characterized in that: The horizontal distance between the load-bearing steel plate (13) and the four sides of the bottom of the precast recycled concrete pier (1) and the four sides of the socket is not less than 20 mm, and the vertical distance between the load-bearing steel plate (13) and the bottom surface of the precast recycled concrete pier (1) is not less than 20 mm, and the horizontal resistance device (10) located inside the recycled concrete foundation (4) is fixed to the foundation longitudinal steel bars (8) and the foundation stirrups (9) by welding.

5. The FRP composite reinforced recycled concrete prefabricated assembly pier column-foundation socket joint according to claim 1, characterized in that: The high-strength concrete UHPC (7) has a compressive strength of not less than 120 MPa and a tensile strength of not less than 10 MPa.

6. The FRP composite reinforced recycled concrete prefabricated assembly pier column-foundation socket joint according to claim 1, characterized in that: The number of the pier body longitudinal FPR composite bars (2) extending out of the precast recycled concrete pier column (1) is 1 / 2-1 / 4 times the total number of the pier body longitudinal FPR composite bars (2) in the precast recycled concrete pier column (1); and the socket depth of the precast recycled concrete pier column (1) is not less than 0.6 times the side length of the precast recycled concrete pier column (1).

7. The FRP composite reinforced recycled concrete prefabricated assembly pier column-foundation socket joint according to claim 1, characterized in that: The inner diameter of the pre-buried metal corrugated pipe (5) is 20-40 mm larger than the longitudinal FPR composite reinforcement (2) of the pier body, or the inner diameter is 60 mm, whichever is greater, and the thickness is not less than 2 mm; the inner diameter of the pre-buried grouting high-pressure pipe (6) is 20-40 mm, and the wall thickness is not less than 0.5 mm.

8. The FRP composite reinforced recycled concrete prefabricated assembly pier column-foundation socket joint according to claim 1, characterized in that: A 10-30 mm thick mortar layer (19) is provided between the bottom surface of the prefabricated recycled concrete pier (1) and the bottom surface of the socket of the recycled concrete foundation (4).

9. The FRP composite reinforced recycled concrete prefabricated assembly pier column-foundation socket joint according to claim 1, characterized in that: The foundation stirrups (9) inside the recycled concrete foundation (4) are arranged around the socket, pass through the middle of the recycled concrete foundation (4) and overlap with the foundation longitudinal steel bars (8).

10. A construction method for prefabricated assembly of FRP composite reinforced recycled concrete pier-foundation socket joints according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Tie the longitudinal FPR composite bars (2) of the pier body, the stirrups (3) of the pier body and the pre-buried metal corrugated pipe (5) of the pier body in the factory. After the pier body longitudinal FPR composite bars (2) and the stirrups (3) of the pier body are tied, a steel grid is formed, the formwork is supported, the recycled concrete is poured, the test piece is cured, the formwork is removed, and the production of the prefabricated recycled concrete pier column (1) is completed. S2. Process the T-shaped longitudinal steel beam (11), cross-shaped longitudinal steel beam (12), load-bearing steel plate (13), horizontal connecting steel plate (14), vertical connecting steel plate (15), anchoring steel plate (16), load-bearing steel plate support (17) and middle reinforcing connecting steel plate (18) of the horizontal resistance device (10) in the factory, weld the load-bearing steel plate (13) and anchoring steel plate (16) to one end of the T-shaped longitudinal steel beam (11) and the cross-shaped longitudinal steel beam (12) respectively, and then reinforce the load-bearing steel plate (13) and the anchoring steel plate (16) by using the middle reinforcing steel plate (18) to strengthen the load-bearing steel plate (13). The strong connecting steel plate (18) connects and welds the T-shaped longitudinal steel beam (11) and the cross-shaped longitudinal steel beam (12), and is welded to the load-bearing steel plate (13), the anchoring steel plate (16) and the middle strengthening connecting steel plate (18) through the horizontal connecting steel plate (14) and the vertical connecting steel plate (15). The load-bearing steel plate support (17) is obliquely welded to the upper part of the T-shaped longitudinal steel beam (11) and the side of the load-bearing steel plate (13) to form an integral load-bearing steel skeleton, thereby completing the production of the horizontal resistance device (10); S3. Tie the foundation longitudinal steel bars (8) and foundation stirrups (9) of the recycled concrete foundation (4) on site, reserve a socket for placing the prefabricated recycled concrete pier (1), and horizontally place the horizontal resistance devices (10) processed and manufactured in the factory on the four sides of the socket. The horizontal resistance devices (10) located inside the recycled concrete foundation (4) are fixed to the foundation longitudinal steel bars (8) and foundation stirrups (9) by welding, so that each load-bearing steel plate (13) is parallel to the four side surfaces of the socket, and a metal corrugated pipe (5) is embedded in the bottom surface of the socket. The pre-buried grouting high-pressure pipe (6) at the bottom edge of the pre-buried metal bellows (5) extends to the top surface of the recycled concrete foundation (4) to serve as a grouting channel. The upper end of the metal bellows grouting outlet (20) at the upper end of the pre-buried metal bellows (5) is parallel to the bottom surface of the socket of the recycled concrete foundation (4). The pre-buried grouting high-pressure pipe (6) connected to the lower end of the pre-buried metal bellows (5) and the metal bellows grouting outlet (20) welded at the lower end are both vertically limited to the four sides of the socket. The template is supported, the recycled concrete is poured, the components are maintained, the template is removed, and the production of the recycled concrete foundation (4) is completed. S4, transport the prefabricated recycled concrete pier column (1) to the construction site, lay a 10-30mm mortar layer (19) on the bottom surface of the socket of the recycled concrete foundation (4), insert the load-bearing steel plate (13) of the four sides of the bottom of the prefabricated recycled concrete pier column (1) parallel to the horizontal resistance device (10) on all sides into the socket, extend the longitudinal FPR composite reinforcement (2) of the pier body of the prefabricated recycled concrete pier column (1) vertically into the interior of the embedded metal corrugated pipe (5), adjust the horizontality and verticality of the prefabricated recycled concrete pier column (1), and complete the placement of the prefabricated recycled concrete pier column (1); S5. Mix high-strength concrete UHPC (7) on site, use a grouting device to fill the pre-buried grouting high-pressure pipe (6) with high-strength concrete UHPC (7), use a grouting method to pour high-strength concrete UHPC (7) through the top of the pre-buried grouting high-pressure pipe (6), wait for the high-strength concrete UHPC (7) to overflow from the grouting outlets (20) of each metal corrugated pipe, ensure that the corrugated pipe is fully grouted, and pour high-strength concrete UHPC (7) between the four sides of the bottom of the prefabricated recycled concrete pier column (1) and the four sides of the socket of the recycled concrete foundation (4), so that the prefabricated recycled concrete pier column (1) and the recycled concrete foundation (4) are connected into a whole, completing the assembly work of the prefabricated recycled concrete pier column (1) and the recycled concrete foundation (4).

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