A shear stud-double steel pipe prefabricated bridge pier and its construction method

Abstract

This invention proposes a shear stud-double steel pipe high-strength prefabricated bridge pier and its construction method. The prefabricated bridge pier includes a precast concrete pier column, the bottom of which is welded to a circular slotted steel pipe via a connecting steel plate; a concrete cap, located at the bottom of the prefabricated bridge pier; and a high-strength connecting section, through which the precast concrete pier column and the concrete cap are fixedly connected. This invention enables rapid positioning and fixing of the circular steel pipe at the bottom of the precast concrete pier column and the shear studs in the steel sleeve at the top of the concrete cap, providing the advantage of self-stabilization of the assembled segments. It not only solves the problem of requiring complex supports for the installation of existing prefabricated pier columns and concrete caps, greatly simplifying the construction process, but also solves the problems of complex concrete construction and inability to achieve dense pouring in the connecting sections of existing prefabricated bridge piers, ensuring the high strength of the assembled connecting sections and enhancing reliability and safety.

Description

Technical Field

[0001] This invention relates to the field of bridge engineering construction technology, and in particular to a shear stud-double steel pipe prefabricated bridge pier and its construction method. Background Technology

[0002] my country's transportation infrastructure construction is currently experiencing a period of rapid development. Prefabricated bridge pier segmental assembly technology involves modularly disassembling the pier vertically into several components, which are then prefabricated in a factory and transported to the construction site for segmental assembly. Compared to cast-in-place bridge piers, this technology offers advantages such as shorter construction time, controllable factory quality, less environmental pollution, and reduced labor costs.

[0003] In recent years, my country has adopted the pre-embedded steel rebar connection sleeve technology in the construction of prefabricated bridge piers. This technology involves pressure grouting of the sleeves to connect multiple pier segments, a complex grouting process that results in high production costs, especially for piers with a large number of segments. To overcome this drawback, researchers have proposed threading prestressed steel strands through pre-drilled holes in the columns to connect prefabricated column segments into a whole. However, the prestressed steel rebars are susceptible to corrosion, affecting the structure's durability. To overcome the shortcomings of the above-mentioned pier connection methods, a novel assembly method for prefabricated concrete pier segments is urgently needed. This invention proposes a shear stud-double steel pipe high-strength prefabricated bridge pier and its construction method. It utilizes slotted round steel pipes and shear studs for efficient installation and positioning, eliminating the need for complex support installation to maintain pier segment stability, thus simplifying the construction method. The use of UHPC ultra-high performance concrete to reinforce the connection between the prefabricated concrete pier and the concrete abutment enhances the energy dissipation capacity of the plastic hinge zone. This technology offers significant advantages, strong engineering applicability, and promising application prospects. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a shear stud-double steel pipe high-strength prefabricated bridge pier and its construction method. This method rapidly positions and fixes the circular steel pipe at the bottom of the precast concrete pier column and the shear studs in the steel casing at the top of the concrete abutment. It offers the advantage of self-stabilization of the assembled segments, not only solving the problem of complex support requirements for installing prefabricated pier columns and concrete abutments in existing systems, greatly simplifying the construction process, but also resolving the issues of complex concrete construction and inability to achieve dense pouring in the connecting sections of existing prefabricated bridge piers. This ensures high strength in the assembled connecting sections, enhancing reliability and safety. Furthermore, this invention uses double steel pipes to locally reinforce the plastic hinge area at the pier bottom, improving the pier's shear resistance and seismic energy dissipation capacity. With its simple structure and high construction efficiency, this invention possesses significant technical advantages and broad application prospects.

[0005] Technical solution:

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0007] Precast concrete piers include slotted circular steel pipes, concrete segments, steel mesh, and connecting steel plates;

[0008] A concrete foundation is located at the bottom of the prefabricated bridge pier, and a positioning slot is reserved in the center of the concrete foundation.

[0009] The high-strength connection section, including a steel casing, shear studs, and UHPC material, is used to connect precast concrete piers and concrete caps; the inner wall of the steel casing is provided with multiple rows of vertically arranged shear studs.

[0010] The slotted round steel pipe has one end connected to the connecting steel plate at the center of the bottom of the precast concrete pier, and the other end passes through the steel sleeve and is inserted into the positioning hole slot at the top of the concrete foundation.

[0011] The slotted round steel pipe has multiple vertical slots on its wall to avoid multiple rows of shear nails, and each vertical slot has a horizontal groove corresponding to the position of multiple shear nails in each row.

[0012] By rotating the slotted round steel pipe, the shear studs are inserted into the transverse groove, thereby achieving the positioning between the precast concrete pier and the concrete foundation.

[0013] Furthermore, the bottom of the steel casing is fixedly connected to the concrete foundation, the upper end is open and welded to the connecting steel plate, and two grouting channels are reserved at the bottom of the casing wall and two grout outlet channels are reserved at the top.

[0014] UHPC material is injected into the steel casing through the grouting channel, and overflows through the top grout outlet channel; the UHPC material is used to connect the slotted round steel pipe and the shear studs inside the steel casing.

[0015] The steel casing is a square steel pipe, which is welded to the internal steel mesh of the concrete foundation and is firmly connected to the upper surface of the concrete foundation through concrete.

[0016] Furthermore, the bottom of the precast concrete pier is provided with a connecting steel plate, which is connected to the precast concrete pier internal steel mesh by through-hole plug welding; the upper part of the slotted round steel pipe is welded to the connecting steel plate.

[0017] Furthermore, the UHPC material has a compressive strength of not less than 120 MPa and a slump expansion of not less than 700 mm.

[0018] The steel casing, connecting steel plate, and slotted round steel pipe are made of Q235 steel with a yield strength of 235MPa.

[0019] The axial height h1 of the slotted round steel pipe is not less than 1 / 3 of the total height H of the precast concrete pier column;

[0020] The diameter d2 of the positioning hole groove is not less than 200mm, and the depth d3 is not less than 100mm.

[0021] Furthermore, the construction method for the shear stud-double steel pipe high-strength prefabricated bridge pier is characterized by including the following steps:

[0022] S1. Weld the upper part of the slotted round steel pipe to the bottom surface of the connecting steel plate, and then weld the top surface of the connecting steel plate to the longitudinal steel bars inside the precast concrete pier.

[0023] S2. Set up a template for the internal steel mesh of the precast concrete pier and pour the precast concrete pier. The precast concrete pier (1) is completed.

[0024] S3. Weld shear studs symmetrically inside the steel casing, weld the bottom of the steel casing to the concrete foundation reinforcement, set up the formwork and pour the concrete foundation, and the concrete foundation is completed.

[0025] S4. Hoist the precast concrete pier column, accurately position the slotted round steel pipe at the bottom of the precast concrete pier column with the positioning hole groove of the concrete foundation, and gradually lower the precast concrete pier column so that the shear nail passes through the vertical slot of the slotted round steel pipe.

[0026] S5. Rotate the precast concrete pier column clockwise by 30° to align the horizontal grooves of the shear studs and the slotted round steel pipe. At this point, the positioning of the precast concrete pier column is complete. Weld the top surface of the steel sleeve box and the connecting steel plate to complete the installation of the precast concrete pier column.

[0027] S6. Pressurize the grouting channel of the steel casing using grouting equipment and inject UHPC material into the internal space of the steel casing from bottom to top. Stop grouting when the UHPC material slurry flows out stably from the slurry outlet channel of the steel casing, and seal the grouting channel and the slurry outlet channel. At this point, the entire construction process is completed.

[0028] Beneficial effects:

[0029] (1) The shear stud-double steel pipe high-strength prefabricated bridge pier proposed in this invention has the advantage of rapid installation without support during construction. The shear studs of the round steel pipe at the bottom of the precast concrete pier column and the steel sleeve box at the top of the concrete cap are quickly positioned and fixed. The round steel pipe is accurately positioned through the holes and grooves at the bottom of the concrete cap. This solves the problem of the need to set up complex supports for the installation of existing prefabricated pier columns and concrete caps, and overcomes the problem of difficulty in controlling the verticality of the pier body. It not only ensures the reliability and safety of the pier assembly process, but also greatly simplifies the construction process.

[0030] (2) The novel connection section between the pier and the concrete cap proposed in this invention has the advantages of high strength and high ductility. By pressure grouting UHPC high-performance concrete material through the pre-reserved duct at the bottom of the steel casing, the cavity of the steel casing and the round steel pipe of the concrete cap is filled. By utilizing the constraint effect of the steel pipe on the concrete, the plastic hinge area at the bottom of the pier is locally reinforced by the steel casing, which improves the shear and bending strength of the pier, enhances the deformation capacity of the plastic hinge of the pier, and can effectively reduce the residual displacement of the pier. It has outstanding advantages in post-earthquake repair and emergency reinforcement.

[0031] (3) The double steel pipe reinforced pier connection section proposed in this invention has the feature of automatic compaction of poured concrete. In high-intensity seismic areas, the requirements for dissipating seismic energy in the plastic hinge area of ​​the pier are high. The steel casing structure of this invention ensures the compactness of the filled UHPC high-performance concrete material, which not only solves the problem of complex concrete construction process and inability to pour compacted concrete in the connection section of existing prefabricated piers, but also ensures the firmness of component assembly and effectively enhances the energy dissipation capacity of the plastic hinge area. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a shear stud-double steel pipe high-strength prefabricated bridge pier according to the present invention;

[0033] Figure 2 This is a schematic diagram of the precast concrete pier structure of the present invention;

[0034] Figure 3 This is a schematic vertical cross-sectional view of the precast concrete pier column of the present invention;

[0035] Figure 4 This is a schematic diagram of the horizontal cross-section of the upper section of the precast concrete pier column of the present invention;

[0036] Figure 5 This is a schematic diagram of the horizontal cross-section of the lower section of the precast concrete pier column of the present invention;

[0037] Figure 6 This is a three-dimensional schematic diagram of the precast concrete pier column with slotted circular steel pipe according to the present invention;

[0038] Figure 7 This is a schematic diagram of the elevation of the precast concrete pier with slotted steel pipe according to the present invention;

[0039] Figure 8 This is a schematic diagram of the precast concrete pier column slotted steel pipe of the present invention;

[0040] Figure 9 This is a schematic diagram of the cast-in-place concrete foundation of the present invention;

[0041] Figure 10 This is a schematic diagram of the steel casing of the present invention;

[0042] Figure 11This is a schematic vertical cross-sectional view of the steel casing of the present invention;

[0043] Figure 12 This is a schematic diagram of the horizontal cross-section of the steel casing of the present invention;

[0044] Figure 13 This is a schematic diagram of the longitudinal positioning of the precast concrete pier and the foundation in the construction method of the present invention;

[0045] Figure 14 This is a schematic diagram of the rotating assembly of the slotted steel pipe in the construction method of the present invention for the precast concrete pier column.

[0046] Figure 15 This is a schematic diagram of grouting of the connecting section steel casing in the construction method of the present invention.

[0047] Explanation of reference numerals in the attached drawings: 1-Precast concrete pier; 2-Concrete cap; 3-High-strength connection section; 4-Slotted round steel pipe; 41-Upper part of steel pipe; 42-Middle part of steel pipe; 43-Lower part of steel pipe; 44-Vertical joint; 45-Horizontal groove; 5-Concrete segment; 6-Reinforcing mesh; 61-Longitudinal reinforcement; 62-Transverse reinforcement; 7-Connecting steel plate; 8-Positioning hole / groove; 9-Shear stud; 10-Steel sleeve; 11-Grouting channel; 12-Grouting channel; 13-UHPC material. Detailed Implementation

[0048] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0049] The following describes, with reference to the accompanying drawings, a shear stud-double steel pipe prefabricated bridge pier and its construction method according to an embodiment of the present invention. Specific implementation method:

[0050] like Figure 1 As shown in this embodiment, the shear stud-double steel pipe high-strength prefabricated bridge pier and its construction method include: a precast concrete pier column 1, a concrete cap 2 and a high-strength connecting section 3, wherein the precast concrete pier column 1 and the concrete cap 2 are fixedly connected by the high-strength connecting section 3.

[0051] like Figure 2 , 3 As shown, the precast concrete pier 1 includes a slotted circular steel pipe 4, a concrete segment 5, a steel mesh 6, and a connecting steel plate 7.

[0052] like Figure 4 , 5 As shown, the internal steel mesh 6 of the precast concrete pier column 1 is connected to the connecting steel plate 7 by through-hole plug welding.

[0053] like Figure 6 , 7 As shown, the slotted round steel pipe 4 includes an upper part 41, a middle part 42 and a lower part 43, located at the bottom center of the precast concrete pier 1, with a longitudinal extension length l1 of not less than 500 mm and not less than 1 / 3 of the total height h1 of the precast concrete pier 1.

[0054] like Figure 8 The central part 42 of the slotted round steel pipe 4 shown is machined longitudinally with four rows of symmetrical vertical slots 44 and horizontal grooves 45. The horizontal grooves 45 are aligned and installed with the shear nails 9 inside the steel sleeve box 10.

[0055] The upper part 41 of the steel pipe and the connecting steel plate 7 are welded together, and the lower part 43 of the steel pipe is aligned with the positioning hole groove 8. The connecting steel plate 7 is located at the bottom of the precast concrete pier 1 and is welded to the internal steel mesh 6 of the precast concrete pier 1.

[0056] like Figure 9 As shown, the concrete pier cap 2 is located at the bottom of the prefabricated bridge pier, and the concrete pier cap 2 has a pre-reserved positioning hole groove 8 in the center.

[0057] like Figure 10 , 11 As shown in Figure 12, the bottom end of the steel casing 10 is fixedly connected to the concrete foundation 2, the upper end is open and welded to the connecting steel plate 7, the inner wall of the steel casing 10 is provided with multiple rows of shear nails 9 arranged vertically, the bottom of the casing wall of the steel casing 10 is reserved with two grouting channels 12, and the top is reserved with two grout outlet channels 11.

[0058] The steel casing 10 is filled with UHPC material 13 through the grouting channel 12, and the UHPC material 13 overflows through the top grout outlet channel 11; the UHPC material 13 is used to connect the slotted round steel pipe 4 and the shear nail 9 inside the steel casing.

[0059] like Figures 13-15 As shown, the present invention discloses a construction method for a shear stud-double steel pipe prefabricated bridge pier, comprising the following construction steps:

[0060] S1. The upper part of the steel pipe and the connecting steel plate are welded together, and the lower part of the steel pipe is aligned with the positioning hole and groove; then the internal steel mesh of the precast concrete pier column is welded to the connecting steel plate through holes.

[0061] S2. Erect formwork for the internal steel mesh of the precast concrete pier; weld the steel casing to the concrete foundation steel reinforcement, support the formwork and pour the concrete foundation, and the precast concrete pier and concrete foundation are completed.

[0062] S3. After the precast concrete pier meets the strength requirements, the precast concrete pier is hoisted and the square steel pipe at the bottom of the precast concrete pier is precisely positioned with the positioning hole groove of the concrete foundation. The precast concrete pier is then lowered step by step so that the shear nail passes through the vertical seam of the slotted round steel pipe 4.

[0063] S4. Rotate the precast concrete pier column clockwise by 30° to align the horizontal grooves of the shear studs and the slotted round steel pipe 4. At this point, the positioning of the precast concrete pier column is complete. Weld the top surface of the steel sleeve box and the connecting steel plate to complete the installation and positioning.

[0064] S6. Pressurize the grouting channel of the steel casing with grouting equipment and inject UHPC material into the internal space of the steel casing from bottom to top. Stop grouting when the UHPC material slurry flows out stably from the slurry outlet channel on the precast concrete pier shell wall. Seal the grouting channel 12 and the slurry outlet channel 11. The construction is now complete.

[0065] Finally, it should be noted that the accompanying drawings are merely illustrative and represent only schematic diagrams, not actual physical images, and should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some common structures and their descriptions may be omitted in the drawings. The above preferred embodiments are only used to illustrate the technical solutions of the invention and are not intended to limit it. Although the invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes in form and detail can be made without departing from the scope defined by the claims of the invention.

Claims

1. A shear stud-double steel pipe high-strength prefabricated bridge pier, characterized in that, include: The precast concrete pier (1) includes a slotted circular steel pipe (4), a concrete segment (5), a steel mesh (6), and a connecting steel plate (7). The concrete foundation (2) is located at the bottom of the prefabricated bridge pier, and the center of the concrete foundation (2) has a pre-reserved positioning hole (8). The high-strength connection section (3) includes a steel casing (10), shear studs (9) and UHPC material (13) for connecting the precast concrete pier (1) and the concrete cap (2); the inner wall of the steel casing (10) is provided with multiple rows of shear studs (9) arranged vertically. The slotted round steel pipe (4) has one end connected to the connecting steel plate (7) at the center of the bottom of the precast concrete pier (1), and the other end passes through the steel sleeve box (10) and is inserted into the positioning hole groove (8) at the top of the concrete foundation (2). The slotted round steel pipe (4) has multiple vertical slots (44) on its wall to avoid multiple rows of shear nails (9). Each vertical slot (44) has a horizontal groove (45) corresponding to the position of each row of multiple shear nails (9). By rotating the slotted round steel pipe (4), the shear nail (9) is inserted into the transverse groove (45) to achieve positioning between the precast concrete pier (1) and the concrete foundation (2); the bottom end of the steel sleeve box (10) is fixedly connected to the concrete foundation (2).

2. The shear stud-double steel pipe high-strength prefabricated bridge pier according to claim 1, characterized in that: The upper end of the steel casing (10) is open and welded to the connecting steel plate (7). Two grouting channels (12) are reserved at the bottom of the casing wall of the steel casing (10), and two grout outlet channels (11) are reserved at the top. UHPC material (13) is injected into the steel casing (10) through the grouting channel (12), and overflows through the top grout outlet channel (11); the UHPC material (13) is used to connect the slotted round steel pipe (4) and the shear nail (9) inside the steel casing (10). The steel casing (10) is a square steel pipe, which is welded to the internal steel mesh of the concrete foundation (2) and is firmly connected to the upper surface of the concrete foundation (2) through concrete.

3. The shear stud-double steel pipe high-strength prefabricated bridge pier according to claim 1, characterized in that: The bottom of the precast concrete pier (1) is provided with a connecting steel plate (7), which is connected to the precast concrete pier (1) through a hole plug welded to the steel mesh (6) reserved inside the precast concrete pier (1); the upper part (41) of the slotted round steel pipe (4) is welded to the connecting steel plate (7).

4. The shear stud-double steel pipe high-strength prefabricated bridge pier according to claim 1, characterized in that: The UHPC material (13) has a compressive strength of not less than 120 MPa and a slump expansion of not less than 700 mm. The steel casing (10), connecting steel plate (7) and slotted round steel pipe (4) are made of Q235 steel with a yield strength of 235MPa. The axial height h1 of the slotted round steel pipe (4) is not less than 1 / 3 of the total height H of the precast concrete pier (1); The diameter d2 of the positioning hole groove (8) is not less than 200mm and the depth d3 is not less than 100mm.

5. The construction method of the shear stud-double steel pipe high-strength prefabricated bridge pier according to any one of claims 1 to 4, characterized in that, Includes the following steps: S1. Weld the upper part (41) of the slotted round steel pipe (4) and the bottom surface of the connecting steel plate (7) together, and then weld the top surface of the connecting steel plate (7) to the longitudinal steel bar (61) inside the precast concrete pier (1). S2. Erect a formwork for the internal steel mesh (6) of the precast concrete pier (1), and pour the precast concrete pier (1) to complete the production of the precast concrete pier (1); S3. Weld the shear nails (9) symmetrically inside the steel casing (10), weld the bottom of the steel casing (10) to the steel reinforcement of the concrete foundation (2), and pour the concrete foundation (2) with the formwork. The concrete foundation (2) is then completed. S4. Hoist the precast concrete pier (1), accurately position the slotted round steel pipe (4) at the bottom of the precast concrete pier (1) with the positioning hole (8) of the concrete foundation (2), and gradually lower the precast concrete pier (1) so that the shear nail (9) passes through the vertical slot (44) of the slotted round steel pipe. S5. Rotate the precast concrete pier (1) clockwise horizontally by 30° to align the shear nail (9) and the horizontal groove (45) of the slotted round steel pipe. At this time, the positioning of the precast concrete pier (1) is completed. Weld the top surface of the steel sleeve box (10) and the connecting steel plate (7) to complete the installation of the precast concrete pier (1). S6. Pressurize the grouting channel (12) of the steel casing (10) with grouting equipment and inject UHPC material (13) into the internal space of the steel casing (10) from bottom to top. Stop grouting when the UHPC material (13) slurry flows out steadily from the slurry outlet channel (11) of the steel casing (10), and seal the grouting channel (12) and the slurry outlet channel (11). The entire construction process is now complete.

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