Hollow steel pipe concrete pier column-bent cap joint structure and construction method

Abstract

The invention relates to a hollow steel pipe concrete pier column-cover beam joint structure and a construction method, and belongs to the technical field of structural engineering. The structure is composed of a hollow steel tube concrete pier column and a prefabricated cover beam, an overhanging section of the hollow steel tube concrete pier column penetrates into and is fixed in a socket hole of the prefabricated cover beam, a lattice angle steel stiff framework is arranged in the hollow steel tube concrete pier column, and the lattice angle steel stiff framework comprises angle steel column limbs, octagonal steel batten plates and socket hole plugging steel plates; a shear key and a blocking steel plate are further arranged on the outwards extending angle steel column limb; uHPC grouting materials are poured into the socket holes, so that the outward extending section of the hollow steel pipe concrete pier column is effectively anchored into the prefabricated cover beam. The hollow steel pipe concrete pier column further comprises a prefabricated pier column, a pier column hollow layer and a pier column outer wrapping steel pipe. The invention aims to optimize the structure of the pier stud-cover beam joint, give play to the advantages of the concrete filled steel tube and the lattice angle steel framework, improve the anti-seismic property of the joint, and provide a brand new technical solution for the application of the concrete filled steel tube pier stud-cover beam joint.

Description

Technical Field

[0001] This invention relates to the construction and method of hollow steel tube concrete pier-cap beam joint, belonging to the field of structural engineering technology. Background Technology

[0002] Precast bridge piers offer advantages such as high construction efficiency, controllable quality, reduced labor costs, reduced environmental pollution, and higher construction safety, leading to their increasing application in modern bridge engineering and a rapid development trend. Because the production and fabrication of precast bridge piers are factory-based and standardized, they require large transport vehicles to be delivered to the construction site and hoisted by appropriate lifting equipment. Therefore, the ease of construction and assembly of bridge piers is of paramount importance.

[0003] In existing precast pier-cap beam connection nodes, the vast majority of connections are made using grouted corrugated pipes. In this method, the longitudinal reinforcement of the pier column is inserted into the corresponding corrugated pipe inside the cap beam, requiring high assembly precision and having a low tolerance for construction errors. Meanwhile, in traditional precast pier-cap beam connections, the precast pier column requires first binding the pier column reinforcement cage and then pouring pier column concrete to complete the precast pier column. This process involves many steps and is quite cumbersome. Furthermore, the longitudinal reinforcement on the side connecting the pier column and the cap beam often extends outwards for assembly and connection of the pier-cap beam node, thus limiting the ductility of the precast pier and hindering the improvement of the seismic performance of the precast pier-cap beam connection node. In existing precast pier-cap beam joints, in order to ensure the bending and compressive strength of the precast pier column section, the pier column section is mostly solid. While ensuring the mechanical performance of the pier column, this results in a large volume and weight of the pier column. On-site transportation and hoisting require a lot of manpower, material resources and financial resources. The convenience of construction and the overall economic benefits of the pier-cap beam joint need to be further improved.

[0004] In summary, in existing precast pier-cap beam joints, further optimization of the joint structure is needed to simplify the joint production and fabrication process, reduce the labor time spent in the production and fabrication process, and at the same time, while ensuring the seismic performance of the pier-cap beam joint, further reduce the overall weight of the precast pier, optimize the joint connection form, reduce the precision of joint assembly construction, and improve the overall construction convenience of the joint. This is of great significance for promoting the application and development of precast pier structure systems. Summary of the Invention

[0005] To address the aforementioned deficiencies in the existing technology, this invention proposes a hollow steel tube concrete pier-cap beam joint structure and construction method, which solves problems such as cumbersome joint production process, seismic performance of pier-cap beam joint, and low precision of joint assembly construction, thereby improving the overall construction convenience of the joint.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The hollow steel tube concrete pier-cap beam joint structure consists of a hollow steel tube concrete pier and a precast cap beam. The extended section of the hollow steel tube concrete pier extends into and is fixed in the socket of the precast cap beam. A lattice angle steel stiffening skeleton is provided inside the hollow steel tube concrete pier. The lattice angle steel stiffening frame includes angle steel column legs, octagonal steel gusset plates, and socket sealing steel plates; four angle steel column legs are arranged opposite each other along the axis of the hollow steel tube concrete pier column; the octagonal steel gusset plates are welded to the inside of the angle steel column legs and form an integral part with the angle steel column legs; The extended portion of the lattice angle steel stiffened frame extends into the socket hole. The angle steel column of the lattice angle steel stiffened frame extending into the socket hole is also provided with shear keys and a sealing steel plate, thereby forming the extended section of the hollow steel tube concrete pier column. The extended section of the hollow steel tube concrete pier is inserted into the socket of the precast cap beam, and UHPC grout is injected into the socket to effectively anchor the extended section of the hollow steel tube concrete pier into the precast cap beam. The hollow steel tube concrete pier also includes a precast pier, a hollow layer of the pier, and an outer steel pipe of the pier. The hollow layer of the pier and the outer steel pipe of the pier are respectively set inside and outside the lattice angle steel stiffening frame. Concrete is poured between the hollow layer of the pier and the outer steel pipe of the pier, thereby casting the lattice angle steel stiffening frame and the concrete together to form a precast pier.

[0007] Furthermore, the octagonal steel gusset plate is uniformly welded along the entire length of the angle steel column.

[0008] Furthermore, a grouting hole is provided on the precast cap beam at the top of the socket.

[0009] Furthermore, the yield strength of the steel in the angle steel columns and octagonal steel gussets of the lattice angle steel stiffening frame is not less than 345 MPa.

[0010] Furthermore, in the hollow steel tube concrete pier, the yield strength of the steel tube encasing the pier is not less than 345 MPa.

[0011] Furthermore, in the extended section of the hollow steel tube concrete pier, the extended length of the angle steel column of the lattice angle steel stiffening frame is not less than 1.5 times the side length of the precast pier section.

[0012] Furthermore, in the extended section of the hollow steel tube concrete pier, a certain number of shear keys are uniformly welded to the outer side of the angle steel column, while a certain number of shear keys are also uniformly welded to the inner and outer sides of the octagonal steel gusset plates between the angle steel columns, in order to enhance the frictional resistance with the UHPC grouting material.

[0013] Furthermore, the strength of UHPC grouting material shall not be less than 120 MPa.

[0014] Furthermore, the welding socket sealing steel plate is welded to the angle steel column between the extended section of the hollow steel tube concrete pier and the precast pier, and is enclosed at the top of the hollow layer of the pier.

[0015] The construction method for the above-mentioned hollow steel tube concrete pier-cap beam joint includes the following steps: S1. Place the angle steel column into the design position, and weld the octagonal steel gusset plate to each angle steel column to form a lattice angle steel stiffening frame; at the same time, according to the design position, weld the socket sealing steel plate and a certain number of shear keys to the extended section of the angle steel column. S2. After the rigid frame of the lattice angle steel is welded, it is placed in the designed position in the steel pipe of the pier column. At the same time, an inner mold is set inside the steel pipe of the pier column to facilitate the later concrete pouring work inside the precast pier column. S3. Tie the reinforcing cage of the precast cap beam and set the formwork for the socket holes at the design position, and at the same time erect the formwork for the precast cap beam; after the formwork is erected, pour the concrete for the precast pier and the precast cap beam respectively, and carry out curing. S4. After the precast pier concrete and precast cap beam concrete have been cured and the formwork has been removed, insert the angle steel column of the extended part of the lattice angle steel rigid frame into the designated position in the socket hole of the precast cap beam, and inject UHPC grout into the socket hole so that the UHPC grout fills the gap between the extended part of the lattice angle steel rigid frame and the socket hole, and finally complete the assembly of the precast pier and precast cap beam.

[0016] By adopting the above technical solution, the present invention has at least one of the following beneficial effects compared with the prior art: This invention proposes a hollow steel tube concrete pier-cap beam joint structure and construction method. In this pier-cap beam joint structure, the outer side of the pier is encased in a steel tube, which provides radial restraint to the pier concrete. The excellent ductility of the steel tube allows it to work in tandem with the concrete to bear the load, improving the pier's seismic performance. It also serves as a template during pier prefabrication, increasing production efficiency. Simultaneously, a hollow layer is formed along the entire length of the pier concrete core, with a lattice-type angle steel stiffening frame embedded within. The lattice-type angle steel columns extend beyond the pier, and shear keys are evenly distributed on the extended sections for connecting the pier and the cap beam. This also enhances the frictional resistance between the angle steel columns and the grouting material. Socket holes are pre-drilled at the designed locations on the prefabricated cap beam. The extended sections of the lattice-type angle steel columns are inserted into these holes, and UHPC grouting material is injected to connect the pier and the cap beam. In this pier-joint structure, the hollow layer inside the pier reduces its overall weight. The pier is encased in steel pipe with an internally embedded lattice angle steel stiffening frame. This fully utilizes the excellent ductility, bending strength, and compressive strength of steel, improving the seismic performance of the joint and positively impacting the overall economic benefits of the pier-cap beam joint. Specific beneficial effects are as follows: 1. This invention addresses the prefabricated pier-cap beam structure. While achieving prefabrication of the pier-cap beam joint, to further optimize the joint structure and improve its seismic performance, a steel pipe is wrapped around the outside of the pier, and a hollow layer is constructed along the entire length of the pier core. A lattice-type angle steel stiffening frame is pre-embedded inside the pier concrete. The outer steel pipe provides radial restraint to the pier concrete, while the built-in lattice-type angle steel stiffening frame works collaboratively with the pier to share the load, fully utilizing the excellent mechanical properties of steel, such as ductility, compressive strength, and tensile strength, thus improving the seismic performance of the joint. Simultaneously, the built-in lattice-type angle steel column can serve as the connection section between the pier and the cap beam.

[0017] 2. The rigid frame of the lattice angle steel is embedded inside the concrete of the pier column, working together with it. At the connection end between the pier and the cap beam, the lattice angle steel column extends outward from the pier column, which can be used for the connection between the pier column and the cap beam. During the assembly of the pier column and the cap beam, in order to enhance the friction between the lattice angle steel column and the grouting material, a certain number of shear keys need to be evenly distributed on the extended section of the lattice angle steel column. These keys are then inserted into the reserved socket holes of the cap beam, and UHPC grouting material is injected into the holes through the grouting holes. This ensures that the grouting material fills the gap between the angle steel column and the socket hole, thereby achieving effective anchoring of the lattice angle steel column in the hole, and thus achieving a reliable connection between the pier column and the cap beam. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall elevation of the invention; Figure 2 This is the present invention. Figure 1 Schematic diagram of AA section; Figure 3 This is the present invention. Figure 1 A schematic diagram of a BB (Baby Window) diagram; Figure 4 This is a three-dimensional schematic diagram of the present invention; Figure 5 This is a flowchart illustrating the manufacturing process of this invention. Detailed Implementation

[0019] The following is in conjunction with the appendix Figure 1-5 The present invention will be further described in detail below to facilitate a clear understanding of the invention, but these descriptions do not constitute a limitation thereof.

[0020] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] Example 1 As attached Figure 1-4 As shown, the hollow steel tube concrete pier-cap beam joint structure of this embodiment consists of a hollow steel tube concrete pier and a precast cap beam 1. The extended section of the hollow steel tube concrete pier extends into and is fixed within the socket 3 of the precast cap beam 1. A lattice angle steel stiffening frame is provided inside the hollow steel tube concrete pier. Figure 1 As shown, the lattice-type angle steel rigid frame includes angle steel columns 8, octagonal steel gusset plates 7, and socket sealing steel plates 6. Four angle steel columns 8 are arranged opposite each other along the axis of the hollow steel tube concrete pier. The octagonal steel gusset plates 7 are welded to the inner side of the angle steel columns 8, forming an integral unit. The octagonal steel gusset plates 7 are uniformly welded along the length of the angle steel columns 8, thus forming a lattice-type angle steel rigid frame. The arrangement of the octagonal steel gusset plates 7 allows each angle steel column 8 to work collaboratively, jointly bearing the load, and effectively preventing buckling deformation of the angle steel columns 8.

[0023] In this embodiment, the extended portion of the lattice angle steel stiffening frame extends into the socket 3, such as... Figure 1-2As shown, a grouting hole 2 is provided on the precast cap beam 1 at the top of the socket 3, and shear keys 5 and a sealing steel plate 6 are also provided on the angle steel column 8 of the lattice angle steel stiffening frame that extends into the socket 3, thereby forming the extended section of the hollow steel tube concrete pier column to enhance the friction between the angle steel column 8 and the UHPC grouting material 4 in the socket 3 and prevent the UHPC grouting material 4 from flowing out of the socket 3. In this embodiment, in the extended section of the hollow steel tube concrete pier column, a certain number of shear keys 5 are uniformly welded to the outer side of the angle steel column 8, and a certain number of shear keys 5 are also uniformly welded to the inner and outer sides of the octagonal steel gusset plate 7 between the angle steel column 8 to enhance the frictional resistance with the UHPC grouting material 4. In addition, the welded socket sealing steel plate 6 is welded to the angle steel column 8 between the extended section of the hollow steel tube concrete pier column and the precast pier column 10, and is sealed at the top of the hollow layer 11 of the pier column.

[0024] The extended section of the hollow steel tube concrete pier is inserted into the socket 3 of the precast cap beam, and UHPC grout 4 is injected into the socket 3, thereby effectively anchoring the extended section of the hollow steel tube concrete pier into the precast cap beam.

[0025] like Figure 3 As shown, the hollow steel tube concrete pier also includes a precast pier 10, a hollow pier layer 11, and an outer steel pipe 9. The hollow pier layer 11 and the outer steel pipe 9 are respectively located inside and outside the lattice angle steel stiffening frame. Concrete is poured between the hollow pier layer 11 and the outer steel pipe 9, thus casting the lattice angle steel stiffening frame and the concrete together to form the precast pier 10. The outer steel pipe 9 can work together with the precast pier 10 to share the load, and can also eliminate the need for reinforcement of the pier section. It can also serve as a template during the casting and fabrication of the precast pier 10, enhancing the convenience of precast production.

[0026] In this embodiment, the yield strength of the angle steel column 8 and the octagonal steel gusset plate 7 in the lattice angle steel stiffening frame is not less than 345 MPa. In the hollow steel tube concrete pier, the yield strength of the outer steel pipe 9 is not less than 345 MPa. Furthermore, in the extended section of the hollow steel tube concrete pier, the extended length of the angle steel column 8 in the lattice angle steel stiffening frame is not less than 1.5 times the side length of the precast pier 10 section. The strength of the UHPC grouting material 4 is not less than 120 MPa.

[0027] Example 2 like Figure 5 As shown, the construction method of the hollow steel tube concrete pier-cap beam joint structure in Embodiment 1 above includes the following steps: S1. Place the angle steel column 8 in the designed position, and weld the octagonal steel gusset plate 7 to each angle steel column 8 to form a lattice angle steel stiffening frame. At the same time, according to the designed position, weld the socket sealing steel plate 6 and a certain number of shear keys 5 to the extended section of the angle steel column 8.

[0028] S2. After the rigid frame of the lattice angle steel is welded, it is placed in the designed position in the steel pipe 9 of the pier column. At the same time, an inner mold is set inside the steel pipe 9 of the pier column to facilitate the later concrete pouring work in the precast pier column 10.

[0029] S3. Tie the reinforcing cage of the precast cap beam 1, and set the formwork for the socket 3 at the designed position. At the same time, erect the formwork for the precast cap beam 1. After the formwork is erected, pour the concrete for the precast pier 10 and the precast cap beam 1 respectively, and then cure them.

[0030] S4. After the concrete of the precast pier column 10 and the precast cap beam 1 have been cured and the formwork has been removed, insert the angle steel column 8 of the extended part of the lattice angle steel rigid frame into the designated position in the socket hole 3 of the precast cap beam, and inject UHPC grout 4 into the socket hole 3 so that the UHPC grout 4 fills the gap between the extended part of the lattice angle steel rigid frame and the socket hole 3, and finally complete the assembly of the precast pier column 10 and the precast cap beam 1.

[0031] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the structure of the present invention. The arrangement and quantity of the present invention are not limited to this example and can be optimized according to actual engineering conditions. Any modifications, equivalent changes, and decorations made to the above embodiments based on the technical principles of the present invention, without departing from the scope of the present invention, are still within the scope of the present invention.

Claims

1. A hollow steel tube concrete pier-cap beam joint structure, comprising a hollow steel tube concrete pier and a precast cap beam (1), wherein the extended section of the hollow steel tube concrete pier extends into and is fixed within the socket (3) of the precast cap beam (1), characterized in that: The hollow steel tube concrete pier column is equipped with a lattice angle steel stiffening frame. The lattice angle steel stiffening frame includes angle steel column members (8), octagonal steel gusset plates (7), and socket sealing steel plates (6); the four angle steel column members (8) are arranged opposite each other along the axis of the hollow steel tube concrete pier column; the octagonal steel gusset plates (7) are welded to the inside of the angle steel column members (8) and form an integral part with the angle steel column members (8); The extended portion of the lattice angle steel stiffened frame extends into the socket hole (3). The angle steel column (8) of the lattice angle steel stiffened frame extending into the socket hole (3) is also provided with shear key (5) and sealing steel plate (6), thereby forming the extended section of the hollow steel tube concrete pier column. The extended section of the hollow steel tube concrete pier is inserted into the socket (3) of the precast cap beam, and UHPC grout (4) is injected into the socket (3) to effectively anchor the extended section of the hollow steel tube concrete pier into the precast cap beam. The hollow steel tube concrete pier also includes a precast pier (10), a hollow pier layer (11), and an outer steel pipe (9). The hollow pier layer (11) and the outer steel pipe (9) are respectively set inside and outside the lattice angle steel stiffening frame. Concrete is poured between the hollow pier layer (11) and the outer steel pipe (9), thereby casting the lattice angle steel stiffening frame and the concrete together to form a precast pier (10).

2. The hollow steel tube concrete pier-cap beam joint structure according to claim 1, characterized in that: The octagonal steel gusset plate (7) is uniformly welded along the entire length of the angle steel column (8).

3. The hollow steel tube concrete pier-cap beam joint structure according to claim 1, characterized in that: Grouting holes (2) are provided on the precast cap beam (1) at the top of the socket (3).

4. The hollow steel tube concrete pier-cap beam joint structure according to claim 1, characterized in that: The steel yield strength of the angle steel column (8) and octagonal steel gusset plate (7) in the lattice angle steel stiffening frame shall not be less than 345 MPa.

5. The hollow steel tube concrete pier-cap beam joint structure according to claim 1, characterized in that: In the hollow steel tube concrete pier, the yield strength of the outer steel tube (9) of the pier is not less than 345MPa.

6. The hollow steel tube concrete pier-cap beam joint structure according to claim 1, characterized in that: In the extended section of the hollow steel tube concrete pier, the extended length of the angle steel column (8) of the lattice angle steel stiffening frame is not less than 1.5 times the cross-sectional side length of the precast pier (10).

7. The hollow steel tube concrete pier-cap beam joint structure according to claim 6, characterized in that: In the extended section of the hollow steel tube concrete pier, a certain number of shear keys (5) are uniformly welded on the outer side of the angle steel column (8), while a certain number of shear keys (5) are uniformly welded on the inner and outer sides of the octagonal steel gusset plate (7) between the angle steel column (8) to enhance the frictional resistance with the UHPC grouting material (4).

8. The hollow steel tube concrete pier-cap beam joint structure according to claim 7, characterized in that: UHPC grouting material (4) has a strength of not less than 120MPa.

9. The hollow steel tube concrete pier-cap beam joint structure according to claim 8, characterized in that: The welded socket sealing steel plate (6) is welded to the angle steel column leg (8) between the extended section of the hollow steel pipe concrete pier and the precast pier (10), and is enclosed at the top of the hollow layer (11) of the pier.

10. A construction method for a hollow steel tube concrete pier-cap beam joint structure according to any one of claims 1-9, characterized in that, Includes the following steps: S1. Place the angle steel column (8) in the design position, and weld the octagonal steel gusset plate (7) to each angle steel column (8) to form a lattice angle steel stiffening frame; at the same time, according to the design position, weld the socket sealing steel plate (6) and a certain number of shear keys (5) to the extended section of the angle steel column (8). S2. After the rigid frame of the lattice angle steel is welded, it is placed in the designed position in the steel pipe (9) of the pier column. At the same time, an inner mold is set inside the steel pipe (9) of the pier column to facilitate the later concrete pouring work in the precast pier column (10). S3. Tie the steel cage of the precast cap beam (1) and set the template of the socket hole (3) at the design position, and at the same time erect the template of the precast cap beam (1). After the formwork is erected, concrete is poured for the precast piers (10) and precast cap beams (1) respectively, and then cured. S4. After the concrete of the precast pier (10) and the precast cap beam (1) have been cured and the formwork has been removed, insert the angle steel column (8) of the extended part of the lattice angle steel rigid frame into the designated position in the socket (3) of the precast cap beam, and inject UHPC grout (4) into the socket (3) so that the UHPC grout (4) fills the gap between the extended part of the lattice angle steel rigid frame and the socket (3), and finally complete the assembly of the precast pier (10) and the precast cap beam (1).

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