A method for connecting a mid-beam of a fabricated pier column

Abstract

The application provides a method for connecting a middle beam of a fabricated pier column, which comprises the following steps: pouring lower pier columns on both sides, hoisting a prefabricated middle beam between the lower pier columns on both sides after the lower pier columns are hardened, erecting a connecting support, and hoisting an upper pier column above the connecting support; the prefabricated middle beam is internally poured with beam reinforcement along the length direction of the prefabricated middle beam, the beam reinforcement is composed of vertically distributed facade main reinforcement and horizontally arranged plane main reinforcement, and the opening of the vertically distributed facade main reinforcement faces upward. Compared with the prior art, the method has the advantages that the weight of the prefabricated middle beam during assembly is greatly reduced, the prefabricated middle beam is convenient to transport and hoist, the connecting mode among the upper and lower pier columns and the prefabricated middle beam is improved, the upper and lower forces between the upper and lower pier columns are reliable, the exposed reinforcement is connected through the winding reinforcement of the spiral structure, the shear capacity is further increased, and the shear performance and the anti-seismic performance of the prefabricated middle beam are stably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building construction, in particular to a method for connecting a middle tie beam of a fabricated pier column. BACKGROUND

[0002] With the continuous advancement of urbanization in China, traffic congestion problems are becoming increasingly prominent, and gradually becoming a key factor affecting urban development. The development direction of building industrialization brings the development of building assembly. As the preferred solution to the problem of traffic congestion in China, urban bridges have been widely used in large, medium and small cities in China. With the development of prefabricated assembly technology, prefabricated pier columns and tie beams are gradually applied to bridge construction. Prefabricated pier columns can be prefabricated in a factory and standardized, with the advantages of controllable quality, fast construction speed, and no influence of construction environment.

[0003] The bridge pier adopts a pile foundation, two pier columns are provided in a single span, and a tie beam is provided between the two pier columns. The tie beam between the piles is a structure for improving the stress of the column and the pile, and the overall stiffness of the pile or pier is strengthened. The tie beam between the piles located at the middle height position of the pier column is called a middle tie beam, and the tie beam between the piles located at the lower end of the pier column and covered by backfill soil is called a middle tie beam.

[0004] There are two main ways to construct the middle tie beam at present. One is the traditional cast-in-place method, which mainly uses manual binding of steel bars and on-site pouring of concrete. It has high safety performance and good integrity, but a large number of support wet connection shells need to be set up during construction, the appearance quality is not easy to control, the construction period is long, and it has a great impact on urban traffic. The second is the prefabricated assembly type middle tie beam, which pours and produces concrete beams, slabs, columns and other components in a factory, and then transports them to the construction site for assembly and forming. It has fast construction speed and beautiful appearance, but when the middle tie beam is connected with the pier column, the existing prefabricated middle tie beam is transported after being poured and formed by concrete, which is too heavy and needs to be lifted by super-conventional large equipment, which is difficult to construct and requires high site hardening, thereby increasing the overall construction cost. For the mountainous areas with poor traffic conditions, the transportation of large components and the entry of large equipment are difficult, which also limits the application of prefabricated assembly type middle tie beams in mountainous bridges. In the traditional way, the connection between the prefabricated middle tie beam and the pier column usually adopts the connection mode of steel bar direct connection and pressure glue, which leads to poor shear resistance of the connection section and weak anti-seismic ability. The overall performance after assembly is not as good as that of on-site pouring construction. SUMMARY

[0005] The purpose of the present application is to provide a method for connecting a middle tie beam of a fabricated pier column, which solves the problems of large self-weight of the existing prefabricated middle tie beam, difficulty in loading and unloading and assembly, less applicable scenarios, and weak shear resistance and anti-seismic performance after connection and assembly.

[0006] The embodiment of the application is implemented by the following technical scheme: a method for connecting and constructing a middle beam of a fabricated pier column, comprising the following steps:

[0007] S1, pouring the lower pier columns on both sides, after the lower pier columns harden, hoisting the prefabricated middle beam between the lower pier columns on both sides, and making the connecting brackets at both ends of the prefabricated middle beam be located above the lower pier columns on both sides respectively;

[0008] S2, erecting the connecting bracket, the connecting bracket comprises a plurality of main webs symmetrically arranged, the main webs are fixed and connected with the auxiliary webs at positions corresponding to the load-bearing blocks embedded in the top surfaces of the lower pier columns through the partition plates between the adjacent two main webs;

[0009] S3, hoisting the upper pier column above the connecting bracket, and making the load-bearing blocks embedded in the bottom surface of the upper pier column be fixedly connected with the main webs and the auxiliary webs at the corresponding positions respectively;

[0010] S4, a plurality of hoop steels are arranged inside the lower pier column and the upper pier column according to the steel bar design requirements of the pier column, a plurality of embedded steels welded with the hoop steels are arranged equidistantly in a hoop manner, the embedded steels are vertically arranged, the upper ends of the embedded steels extend upward and are connected with threaded sleeves one, the threaded sleeves one corresponding to each other are connected through the exposed steels;

[0011] S5, a plurality of stirrup holes are arranged in the main webs from top to bottom at intervals, the wrapping steels are arranged in a circumferential manner outside the connecting bracket, the wrapping steels have a spiral structure, the wrapping steels pass through the plurality of stirrup holes from top to bottom in sequence and are welded and fixed with the exposed steels;

[0012] S6, the prefabricated middle beam has the beam steels poured in the inside thereof along the length direction thereof in advance, the beam steels are composed of the U-shaped distributed vertical main steels and the horizontally arranged planar main steels, the opening of the U-shaped distributed vertical main steels faces upward, wherein the planar main steels are located at the opening of the U-shaped arranged vertical main steels, and the vertical main steels extend to the directly above of the lower pier column, after the construction of the upper pier column, the exposed steels and the wrapping steels is completed, the length of the planar main steels is extended through the steels and the threaded sleeves two, so that the terminal end of the planar main steels also extends to the directly below of the upper pier column after the extension;

[0013] S7, a wet connection shell is arranged outside the connecting bracket, the wet connection shell completely seals the cavity surrounded by the lower pier column, the upper pier column and the prefabricated middle beam, then the cavity is filled with the concrete poured through the through hole formed in the middle of the upper pier column, after the concrete solidifies and hardens, the wet connection shell is removed, and the middle beam construction of the fabricated pier column is completed.

[0014] Further, the top surface of the lower pier column and the top surface of the upper pier column are respectively provided with installation grooves at positions corresponding to the load-bearing blocks, the size of the installation grooves matches the load-bearing blocks.

[0015] Further in the S1 step, the section at both ends of the prefabricated middle tie beam is in a rectangular structure, and the section at the middle position is in an I-shaped structure.

[0016] Further in the S2 step, the solid structure after normal stretching of the axisymmetric geometry between the partition plate and the main web.

[0017] Further in the S2 step, the auxiliary web is arranged obliquely from the web, and the oblique direction of the auxiliary web is towards the axis of the upper pier column and the lower pier column.

[0018] Further in the S2 step, the main web and the auxiliary web are both provided with a plurality of operation holes.

[0019] Further in the S2 step, the auxiliary web obliquely extends to the inside of the prefabricated middle tie beam and is welded and fixed with the tie beam reinforcement.

[0020] Further in the S6 step, the threaded sleeve two is embedded into the inside of the upper pier column, and the plurality of flat main reinforcements arranged in a flat manner are connected with the threaded sleeve two through reinforcement.

[0021] Further in the S7 step, the wet joint shell is made of UHPC material.

[0022] Further in the S7 step, the reinforcement is mutually staggered with the connecting support during extension.

[0023] The technical scheme of the embodiment of the present application has at least the following advantages and beneficial effects:

[0024] Compared with the traditional technical scheme, the method has the advantages of greatly reducing the weight of the prefabricated middle tie beam during assembly, facilitating transportation and hoisting, facilitating popularization and application in mountainous areas and areas with inconvenient transportation, the connecting support not only reduces the weight of the prefabricated middle tie beam, but also improves the connection mode between the upper and lower pier columns and the prefabricated middle tie beam, the upper and lower forces between the upper and lower pier columns are reliable, the special structure of the tie beam reinforcement and the construction mode also make the connection between the prefabricated middle tie beam and the upper and lower pier columns more close, and the exposed reinforcement is connected through the winding reinforcement of the spiral structure, further increasing the shear capacity, and the shear performance and the anti-seismic performance of the prefabricated middle tie beam are stably improved. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical scheme of the embodiment of the present application, the following will briefly introduce the drawings needed to be used in the embodiment, and it should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0026] Figure 1A construction flow chart of a method for connecting a middle beam of an assembled pier column according to the present application is provided.

[0027] Figure 2 A front view of a single-sided prefabricated middle beam combined with upper and lower pier columns according to the present application is provided.

[0028] Figure 3 A perspective view of a lower pier column according to the present application is provided.

[0029] Figure 4 A Figure 2 A sectional view of the prefabricated middle beam at A-A.

[0030] Figure 5 A Figure 2 A sectional view of the prefabricated middle beam at B-B.

[0031] Figure 6 A sectional view of the prefabricated middle beam at B-B.

[0032] Figure 7 A Figure 6 A sectional view of the prefabricated middle beam at C-C.

[0033] Figure 8 A Figure 6 A sectional view of the prefabricated middle beam at D-D.

[0034] Figure 9 A Figure 6 A top view.

[0035] Figure 10 A top view of the prefabricated middle beam combined with upper and lower pier columns according to the present application is provided.

[0036] Figure 11 A Figure 10 A partial enlarged view at E.

[0037] Figure 12 A front view of a connecting bracket, an upper pier column, and a lower pier column according to the present application is provided.

[0038] Figure 13 A front view of exposed steel bars erected outside the connecting bracket according to the present application is provided.

[0039] Figure 14 A front view of wound steel bars erected outside the connecting bracket according to the present application is provided.

[0040] Icon: 1, lower pier column; 2, embedded steel bars; 21, threaded sleeve 1; 22, mounting groove; 23, bearing block; 3, upper pier column; 4, prefabricated mid-beam; 41, beam steel bars; 411, vertical main bars; 412, horizontal main bars; 413, threaded sleeve 2; 5, main web; 51, secondary web; 52, partition; 53, operation hole; 54, stirrup hole; 6, exposed steel bars; 7, winding steel bars; 8, wet joint shell. DETAILED DESCRIPTION

[0041] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the following will be a clear and complete description of the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0043] As shown in Figure 1 , a prefabricated pier column mid-beam connecting construction method comprises the following steps:

[0044] S1, pouring the lower pier columns 1 on both sides, after the lower pier columns 1 harden, confirming the distance between the two lower pier columns 1, determining the length of the prefabricated mid-beam 4 in the prefabrication yard according to the known distance, and hoisting the prefabricated mid-beam 4 between the lower pier columns 1 on both sides, as shown in Figure 2 and Figure 12 , the structure shown in the figure is only the structure after the prefabricated mid-beam 4 on one side is assembled, so that the connecting brackets at both ends of the prefabricated mid-beam 4 are located above the lower pier columns 1 on both sides;

[0045] S2, installing the connecting bracket, as shown in Figure 6 , Figure 10 and Figure 11 , the connecting bracket comprises a plurality of main webs 5 arranged symmetrically, two adjacent main webs 5 are connected by a partition 52, in this technical solution, the main web 5 and the two partitions 52 form a rectangle, the main web 5 near one end of the prefabricated mid-beam 4 is connected with a secondary web 51, the secondary web 51 and the main web 5 are an integral structure, the secondary web 51 extends to the inside of the prefabricated mid-beam 4 and is welded and fixed with the beam steel bars 41, which can effectively increase the connecting strength of the connecting bracket and the prefabricated mid-beam 4;

[0046] The plan view of the connecting support is an axisymmetric geometric figure, and the three-dimensional structure formed after the geometric figure is normal stretched is the connecting support.

[0047] In the technical solution, the web plate 51 is arranged obliquely, and the oblique direction of the web plate 51 is towards the shaft center of the upper pier column 3 and the lower pier column 1.

[0048] S3, as shown in the figure, Figure 2 The upper pier column 3 is hoisted to the upper side of the connecting support, Figure 3 As shown in the figure, the bottom surface of the upper pier column 3 and the top surface of the lower pier column 1 are provided with a plurality of installation grooves 22, and the installation grooves 22 are fixed with bearing blocks 23, and the size of the installation grooves 22 is matched with the bearing blocks 23, so that the bearing blocks 23 embedded on the bottom surface of the upper pier column 3 and the bearing blocks 23 embedded on the top surface of the lower pier column 1 are fixedly connected with the main web plate 5 and the web plate 51 at the corresponding positions respectively, and the fixing of the connecting support is completed.

[0049] In the technical solution, as shown in the figures, Figure 1 , Figure 4 and Figure 5 The cross section of the middle position of the prefabricated middle beam 4 is in the shape of an I-beam, and the progressive connection section exists between the two structures, which can save materials while not reducing the overall strength, and improve the tensile strength and the anti-seismic ability.

[0050] S4, as shown in the figures, Figure 3 and Figure 13 In the technical solution, a plurality of ring-shaped reinforcement bars are arranged in the lower pier column 1 and the upper pier column 3 according to the reinforcement design requirements of the pier column, and a plurality of embedded reinforcement bars 2 are arranged equidistantly and are welded with the ring-shaped reinforcement bars, the embedded reinforcement bars 2 are vertically arranged, the upper ends of the embedded reinforcement bars 2 extend upward and are connected with threaded sleeves one 21, and the two threaded sleeves one 21 corresponding to each other are connected through exposed reinforcement bars 6.

[0051] In the technical solution, the embedded reinforcement bars 2 are distributed in two circles, and the corresponding exposed reinforcement bars 6 are also distributed in two circles, and the plurality of exposed reinforcement bars 6 are arranged around the two circles with the shaft line of the lower pier column 1 and the upper pier column 3 as the center point.

[0052] S5, as shown in the figures, Figure 12 and Figure 14As shown, the main web plate 5 is provided with a plurality of hoop hole 54 spaced apart from top to bottom, and the winding reinforcement 7 is arranged outside the connecting bracket in a circumferential direction, and the plurality of exposed reinforcement 6 in the inner ring and the plurality of exposed reinforcement 6 in the outer ring are respectively connected and fixed by the winding reinforcement 7, the winding reinforcement 7 is in a spiral structure, and the winding reinforcement 7 sequentially passes through the plurality of hoop holes 54 on the main web plate 5 from top to bottom and is respectively connected with the plurality of exposed reinforcement 6 in the inner and outer rings, and the connecting mode can adopt welding and steel wire binding. Compared with the traditional concrete pier column compression connection, such connecting mode greatly improves the shear resistance and seismic performance of the prefabricated mid-beam 4 after forming, and is convenient and efficient in construction;

[0053] S6, as shown in Figure 6 , Figure 7 and Figure 8 , the prefabricated mid-beam 4 is precast with a beam reinforcement 41 inside along the length direction, the beam reinforcement 41 is composed of U-shaped vertical reinforcement 411 and flat main reinforcement 412 arranged in a plane, the opening of the U-shaped vertical reinforcement 411 faces upward, wherein the flat main reinforcement 412 is located at the opening of the U-shaped vertical reinforcement 411, as shown in Figure 6 and Figure 7 , in the end of the reinforcement section view of the prefabricated mid-beam 4, the vertical reinforcement 411 and the flat main reinforcement 412 form a rectangular arrangement, and when the vertical reinforcement 411 continues to extend outward above the lower pier column 1 and overlaps with the axis of the lower pier column 1, at this time the vertical reinforcement 411 extends directly above the lower pier column 1, as shown in Figure 8 , at this time, as shown in the reinforcement section view, since the length of the flat main reinforcement 412 remains unchanged, only the U-shaped vertical reinforcement 411 is present on the section view, which can leave a gap above the lower pier column 1, which is beneficial for subsequent erection of the upper pier column 3. After the connecting bracket and the upper pier column 3 are erected and the construction of the exposed reinforcement 6 and the winding reinforcement 7 is completed, the restoration of the flat main reinforcement 412 can be carried out to strengthen the connection strength between the prefabricated mid-beam 4 and the lower pier column 1, the connecting bracket and the upper pier column 3;

[0054] As shown in Figure 9 , a threaded sleeve 413 is embedded in the upper pier column 3, and the threaded sleeve 413 and the flat main reinforcement 412 are connected by reinforcement, thereby extending the length of the flat main reinforcement 412, so that the end of the flat main reinforcement 412 also extends directly below the upper pier column 3 after extension. This can enhance the connection strength between the prefabricated mid-beam 4 and the upper pier column 3 during subsequent pouring, improve the tensile strength and seismic capacity of the prefabricated mid-beam 4 after installation and forming, and improve the overall quality of the prefabricated mid-beam 4, and the reinforcement is mutually offset with the connecting bracket during extension;

[0055] S7, as shown in Figure 2 and Figure 14As shown, the wet connection shell 8 is arranged outside the connecting bracket, the wet connection shell 8 is made of UHPC material, the wet connection shell 8 is clamped at the cavity between the upper pier column 3, the prefabricated middle beam 4 and the lower pier column 1, the edges of the three correspond to the positions of the wet connection shell 8 are provided with clamping grooves, the splicing assembly of the wet connection shell 8 is realized, then the concrete can be poured into the cavity from the through hole of the upper pier column 3, until the concrete fills the gap inside the lower pier column 1, the upper pier column 3 and the connecting bracket, after the concrete hardens, the wet connection shell 8 can be removed, and the middle beam construction work of the assembly type pier column is completed.

[0056] In the technical solution, the UHPC wet connection shell 8 is used to close the cavity between the upper and lower pier columns, and the prefabricated middle beam 4 is more closely connected, the construction period is short during construction, the construction difficulty is reduced, the stress is reliable, and the shear resistance and the anti-seismic performance are improved.

[0057] In the technical solution, the main web plate 5 and the slave web plate 51 are provided with a plurality of operation holes 53, the operation holes 53 are beneficial to reduce the weight of the main web plate 5 and the slave web plate 51, so that the material can be saved while the overall strength is not reduced, and the tensile strength and the anti-seismic capacity of the main web plate 5 and the slave web plate 51 are improved, in addition, during the later pouring of the concrete, the operation holes 53 can make the concrete completely wrap each surface of the connecting bracket, so that the concrete and the connecting bracket are more closely integrated.

[0058] In the technical solution, when the wet connection shell 8 is installed, a plurality of screw rods are arranged on the connecting bracket at equal angles in the radial direction, the screw rods pass through the wet connection shell 8, when the wet connection shell 8 is closely combined with the surfaces of the lower pier column 1, the upper pier column 3 and the prefabricated middle beam 4, a nut is used to thread with the screw rod and finally lock the wet connection shell 8, so that the fixing is completed, and the wet connection shell 8 is prevented from being accidentally separated from the upper and lower pier columns and the prefabricated middle beam 4 due to the hardening and expansion of the internal concrete.

[0059] The construction method has the advantages that the weight of the prefabricated middle beam 4 during assembly is greatly reduced, transportation and hoisting are facilitated, the connecting bracket not only reduces the weight of the prefabricated middle beam 4, but also improves the connection mode between the upper and lower pier columns and the prefabricated middle beam 4, the special structure of the embedded threaded sleeve 413 and the construction mode make the connection between the prefabricated middle beam 4 and the upper and lower pier columns more closely, and the spiral structure of the winding steel bars 7 connects the exposed steel bars 6, so that the shear resistance and the anti-seismic performance of the prefabricated middle beam 4 are stably improved.

[0060] The preferred embodiments of the application have been described above, but the application is not limited to the above. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A construction method for connecting the central tie beam of a prefabricated pier column, characterized in that: The method comprises the following steps: S1, pouring the lower pier columns (1) on both sides, after the lower pier columns (1) harden, hoisting the prefabricated middle beam (4) between the lower pier columns (1) on both sides, and making the connecting supports at both ends of the prefabricated middle beam (4) located above the lower pier columns (1) on both sides respectively; S2, erecting the connecting supports, the connecting supports comprise a plurality of main webs (5) arranged symmetrically, two adjacent main webs (5) are connected through the partition plates (52), the main webs (5) and the slave webs (51) are fixed at the positions corresponding to the embedded bearing blocks (23) on the top surfaces of the lower pier columns (1), and the main webs (5) are connected with the slave webs (51) at the ends close to the prefabricated middle beam (4); S3, hoisting the upper pier columns (3) above the connecting supports, and making the bottom surfaces of the upper pier columns (3) embedded with a plurality of bearing blocks (23) fixedly connected with the main webs (5) and the slave webs (51) at the corresponding positions respectively; S4, a plurality of ring-shaped steels are arranged in the lower pier columns (1) and the upper pier columns (3) according to the steel bar design requirements of the pier columns, a plurality of embedded steels (2) are arranged at equal intervals in the ring-shaped steels, the embedded steels (2) are arranged vertically, the upper ends of the embedded steels (2) extend upwards and are connected with the threaded sleeves one (21), the two threaded sleeves one (21) corresponding to each other are connected through the exposed steels (6); S5, a plurality of stirrup holes (54) are arranged in the main webs (5) at intervals from top to bottom, the wrapping steels (7) are arranged on the outer part of the connecting supports in a circumferential direction, the wrapping steels (7) have a spiral structure, the wrapping steels (7) pass through the stirrup holes (54) from top to bottom in sequence and are welded and fixed with the exposed steels (6); S6, the prefabricated middle beam (4) is previously poured with beam steels (41) in the length direction in the interior of the prefabricated middle beam (4), the beam steels (41) are composed of U-shaped vertical main steels (411) and flat main steels (412) arranged in a flat manner, the U-shaped vertical main steels (411) have openings facing upwards, the flat main steels (412) are located at the openings of the U-shaped vertical main steels (411), and the vertical main steels (411) extend to the directly above of the lower pier columns (1), after the construction of the upper pier columns (3), the exposed steels (6) and the wrapping steels (7) is completed, the length of the flat main steels (412) is extended through the steels and the threaded sleeves two (413), so that the ends of the flat main steels (412) also extend to the directly below of the upper pier columns (3) after the extension; S7, a wet connection shell (8) is arranged on the outer part of the connecting supports, the wet connection shell (8) completely seals the cavity surrounded by the lower pier columns (1), the upper pier columns (3) and the prefabricated middle beam (4), then the cavity is filled with concrete poured through the through holes formed in the middle of the upper pier columns (3), after the concrete solidifies and hardens, the wet connection shell (8) is removed, and the middle beam construction of the assembled pier column is completed.

2. The method of claim 1, wherein the method further comprises: The top surface of the lower pier column (1) and the bottom surface of the upper pier column (3) are respectively provided with installation grooves (22) at the positions corresponding to the bearing blocks (23), and the sizes of the installation grooves (22) are matched with the bearing blocks (23).

3. The method of claim 1, wherein the method further comprises: In the S1 step, the sections at both ends of the prefabricated middle beam (4) have a rectangular structure, and the section at the middle position has an I-shaped structure.

4. The method of claim 1, wherein the method further comprises: In the S2 step, the geometric figure between the partition plate (52) and the main web plate (5) is a three-dimensional structure after normal stretching.

5. The method of claim 1, wherein the method further comprises: In the S2 step, the auxiliary web plate (51) is arranged obliquely, and the oblique direction of the auxiliary web plate (51) is towards the shaft center of the upper pier column (3) and the lower pier column (1).

6. The method of claim 1, wherein the method further comprises: In the S2 step, the main web plate (5) and the auxiliary web plate (51) are both provided with a plurality of operation holes (53).

7. The method of claim 5, wherein the method further comprises: The auxiliary web plate (51) extends obliquely to the inside of the prefabricated tie beam (4) and is welded and fixed with the tie beam steel bar (41).

8. The method of claim 1, wherein the method further comprises: In the S6 step, the threaded sleeve two (413) is embedded into the inside of the upper pier column (3), and a plurality of flat main steel bars (412) arranged in a flat manner are connected with the threaded sleeve two (413) through steel bars.

9. The method of claim 1, wherein the method further comprises: In the S7 step, the wet joint shell (8) is made of UHPC material.

10. The method of claim 8, wherein the method further comprises: The steel bars are mutually dislocated with the connecting support in the extension process.

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