Construction method of inclined concrete-filled steel tube columns with internal reinforcement

Abstract

The present invention relates to a method for constructing an inclined steel tube concrete column with internal reinforcement, wherein multiple circles of bolt groups are provided circumferentially within the steel tube, and the steps include: providing an arc-shaped support plate, wherein the length of the arc-shaped support plate is the same as the length of the steel tube, and the diameter of the arc-shaped support plate is not greater than the inner diameter of the entire circle of bolt groups within the steel tube; placing the steel tube flat on the ground, and then pushing the arc-shaped support plate into the steel tube so that the two ends of the arc-shaped support plate are flush with the head and tail ends of the steel tube, respectively, and the outer circumferential surface of the arc-shaped support plate is against the bolts at the bottom of the steel tube. The present invention addresses the difficulties in installing a reinforcement cage within an inclined steel tube, determines the idea of ​​prefabricating the reinforcement cage, fixing it to the steel tube, and hoisting it as a whole, clarifies the spacing between the reinforcement cage and the inner wall of the steel tube, and proposes a non-contact lap connection method between each section of the reinforcement cage; during the installation process, the reinforcement cage within the steel tube is installed by using the support plate to overcome the influence of the bolts within the steel tube, adopting positioning ribs that can be welded in stages to fix the reinforcement cage, and hoisting the reinforcement cage and the steel tube as a whole.

Description

Technical Field

[0001] The invention belongs to the technical field of building construction, and in particular relates to a construction method of an inclined steel tube concrete column with internal steel bars. Background Art

[0002] Concrete-filled steel tube structures (CFSTs) are a novel composite structure formed by pouring concrete into steel tubes. They effectively leverage the respective strengths of both steel and concrete. The steel tubes simultaneously constrain the concrete within, increasing its compressive strength; the concrete within the tubes effectively prevents local buckling of the tubes. The interaction between the steel tubes and concrete transforms the concrete's failure within the tubes from brittle to plastic, significantly improving the component's ductility and energy dissipation capacity, resulting in superior seismic performance. Due to their excellent mechanical properties, CFST columns are increasingly being used in super-high-rise buildings.

[0003] Domestic design specifications generally use studs to reinforce the synergy between steel tubes and concrete columns and generally do not require the installation of steel reinforcement within the concrete within the steel tubes. Due to varying design philosophies, some regional design specifications require that the concrete within steel tube columns be reinforced according to the structural reinforcement ratio. The requirement for reinforcing steel within the steel tubes presents significant challenges for the construction of concrete-filled steel tube columns. The main difficulties are as follows: First, the working space is limited. The interior space of concrete-filled steel tube columns is narrow, and as the height increases, the diameter of the steel tube decreases, making it difficult for workers to enter the steel tube columns to install rebar. Second, the inclination of the steel tube columns complicates installation. Due to the design requirements of super-high-rise buildings, concrete-filled steel tube columns are often tilted, and this inclination affects the hoisting of the rebar cage. Third, studs can collide with the reinforcement cage stirrups. Studs are typically installed on the inner wall of steel tube columns, and collisions between the studs and the reinforcement cage stirrups can occur during installation, complicating the installation of rebar within the steel tube columns. Therefore, we propose a construction method for inclined concrete-filled steel tube columns with internal reinforcement to address these issues. Summary of the Invention

[0004] In order to solve the above problems, the present invention provides a construction method for inclined steel tube concrete columns with internal steel bars, which solves the problem of difficult installation of steel cages.

[0005] The present invention is implemented by the following scheme: a construction method of an inclined steel tube concrete column with internal reinforcement, wherein bolts are provided circumferentially inside the steel tube, and the steps include:

[0006] Provide an arc-shaped support plate, the length of which is the same as the length of the steel pipe, and the diameter of which is no larger than the inner diameter of the entire circle of bolts in the steel pipe;

[0007] Place the steel pipe flat on the ground, then push the curved support plate into the steel pipe and make the two ends of the curved support plate flush with the head and tail ends of the steel pipe respectively, and the outer circumference of the curved support plate rests on the pegs at the bottom of the steel pipe;

[0008] Provide a steel cage unit and push it into the steel pipe along the arc-shaped support plate;

[0009] The tail end of the steel cage unit is welded to the tail end of the steel pipe using the first positioning rib, and the head end of the steel cage unit is welded to the first part of the head end of the steel pipe using the second positioning rib, wherein the first part is the part avoiding the arc-shaped support plate;

[0010] Pull out the arc-shaped supporting plate, and then weld the head end of the steel cage unit and the rest of the head end of the steel pipe to the second positioning rib;

[0011] The steel pipe and steel cage unit are hoisted as a whole to the installation site for installation.

[0012] A further improvement of the construction method of the inclined steel tube concrete column with internal reinforcement of the present invention is that the reinforcement cage unit is a segmented structure, and one end of each segment of the reinforcement cage is formed with a shrinkage head for inserting into the reinforcement cage of the adjacent segment.

[0013] A further improvement of the construction method of the inclined steel tube concrete column with internal steel bars of the present invention is that each section of the steel cage includes longitudinal bars, which are arranged in a ring, and each section of the steel cage also includes stirrups, which are tied around the periphery of the longitudinal bars arranged in a ring.

[0014] A further improvement of the construction method of inclined steel tube concrete columns with internal steel bars of the present invention is that the longitudinal bars include outer vertical bars, inner vertical bars and diagonal bars obliquely connected between the upper end of the outer vertical bars and the lower end of the inner vertical bars, and the part of each section of the steel cage corresponding to the inner vertical bars is formed as the shrinkage head.

[0015] A further improvement of the construction method of the inclined steel tube concrete column with internal reinforcement of the present invention is that the arc-shaped supporting plate is formed by splicing at least two arc-shaped plates, and stiffening plates are welded at the joints between adjacent arc-shaped plates.

[0016] A further improvement of the construction method of the inclined steel tube concrete column with internal steel bars of the present invention is that one end of the arc-shaped support plate is fixedly connected to a ring plate; after the arc-shaped support plate is pushed into the steel tube, the ring plate blocks the head end of the steel tube.

[0017] A further improvement of the construction method of the inclined steel tube concrete column with built-in steel bars of the present invention is that it also includes the steps of: hoisting the steel tube and the steel cage unit as a whole to the installation site for installation, welding the steel tube to connect, reserving a casting hole on the side of the lower end of the steel tube, and pouring concrete through the casting hole by a jacking method to form a steel tube concrete column.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention addresses the difficulties in installing a steel cage in an inclined steel pipe, determines the idea of ​​prefabricating the steel cage, fixing it to the steel pipe, and hoisting it as a whole, clarifies the distance between the steel cage and the inner wall of the steel pipe, and proposes a non-contact overlap connection method between each section of the steel cage; during the installation process, a support plate is used to overcome the influence of the bolts in the steel pipe, the steel cage is fixed with positioning bars that can be welded in stages, and the steel cage and the steel pipe are hoisted as a whole to install the steel cage in the steel pipe, and finally the concrete jacking technology is used to complete the pouring of concrete in the steel pipe; this method is technically reliable, can effectively ensure the construction quality of the inclined steel pipe concrete column with internal steel bars, not only saves costs, but also shortens the construction period, and has good promotion and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the non-contact overlapping of adjacent sections of reinforcement cages in a steel pipe according to the present invention is shown.

[0021] Figure 2 Shown is a schematic diagram of the arc-shaped support plate structure of the present invention.

[0022] Figure 3 A schematic diagram of the welding position of the positioning ribs of the present invention is shown.

[0023] In the figure: 1. Steel pipe; 2. Steel cage unit; 22. Longitudinal reinforcement; 221. External vertical reinforcement; 222. Diagonal reinforcement; 223. Internal vertical reinforcement; 3. Stirrups; 4. Studs; 5. Arc support plate; 51. Arc plate; 52. Stiffening plate; 53. Ring plate; 54. Ear plate; 6. Positioning reinforcement. DETAILED DESCRIPTION

[0024] In order to solve the problem of difficult installation of steel cage, the present invention provides a method for constructing inclined steel tube concrete columns with internal reinforcement. The following is a further description of the method for constructing inclined steel tube concrete columns with internal reinforcement using a specific embodiment and accompanying drawings.

[0025] See Figures 1 to 3As shown, a construction method for an inclined steel tube concrete column with internal reinforcement is shown, wherein a plurality of circles of bolts are provided in the circumferential direction of the steel tube 1, and the steps include: providing an arc-shaped support plate 5, the length of the arc-shaped support plate 5 being the same as that of the steel tube 1, and the diameter of the arc-shaped support plate 5 being no larger than the inner diameter of the four groups of bolts in the entire circle in the steel tube 1; placing the steel tube 1 flat on the ground, and then pushing the arc-shaped support plate 5 into the steel tube 1 so that the two ends of the arc-shaped support plate 5 are respectively flush with the head end and the tail end of the steel tube 1, and the outer circumferential surface of the arc-shaped support plate 5 is in contact with the bolts 4 at the bottom of the steel tube 1; providing a reinforcement cage Unit 2, and push the steel cage unit 2 into the steel pipe 1 along the arc-shaped support plate 5; use the first positioning rib to weld the tail end of the steel cage unit 2 to the tail end of the steel pipe 1, and use the second positioning rib to weld the head end of the steel cage unit 2 to the first part of the head end of the steel pipe 1, the first part is the part avoiding the arc-shaped support plate 5; pull out the arc-shaped support plate 5, and then weld the head end of the steel cage unit 2 and the rest of the head end of the steel pipe 1 to the second positioning rib; hoist the steel pipe 1 and the steel cage unit 2 as a whole to the installation site for installation.

[0026] When the arc-shaped support plate 5 is pushed into the flat steel pipe 1, the bottom of the arc-shaped support plate 5 can be attached to the top of the bolt 4 at the lower end of the steel pipe 1. At this time, the arc-shaped support plate 5 can cover the bolt 4 at the lower end, so that when the steel cage unit 2 is pushed into the steel pipe 1 for installation, there is no uncovered bolt 4 hooking the steel cage unit 2, so that the steel cage unit 2 is not hindered by the bolt 4 during installation; by using positioning ribs 6 at both the head and tail ends to weld the steel cage unit 2 to the steel pipe 1, it can be ensured that the welded steel cage unit 2 and the steel pipe 1 are a whole, so as to facilitate subsequent hoisting and installation, and ensure safety during high-altitude hoisting. In this embodiment, the first positioning rib and the second positioning rib have the same structure and both belong to positioning rib 6, which is a double cross positioning rib.

[0027] Among them, the steel cage unit 2 is a segmented structure, and the steel cage unit 2 is composed of at least two sections of steel cages plugged in, and one end of each section of the steel cage is formed into a shrinkage head for inserting the adjacent section of the steel cage; each section of the steel cage includes longitudinal bars 22, which are arranged along a ring, and each section of the steel cage also includes stirrups 3, which are tied around the outer periphery of the longitudinal bars 22 arranged in a ring; the longitudinal bars 22 include outer vertical bars 221, inner vertical bars 223, and bars obliquely connected between the upper end of the outer vertical bars 221 and the lower end of the inner vertical bars 223. The inclined reinforcement 222 of each section of the steel cage corresponds to the inner vertical reinforcement 223, and the part of each section of the steel cage corresponding to the end of the shrinkage head is formed with a sleeve opening; the sleeve opening and the shrinkage head adopt non-contact overlap, and the distance between the inner side of the sleeve opening and the outer side of the shrinkage head is not more than one fifth of the overlap length or 150mm (the overlap connection between the steel cages does not require direct contact between the steel bars, and a certain distance can be maintained between the steel bars. The size of the distance is determined according to the overlap length, the inclination angle of the steel pipe 1 and the convenience of installation).

[0028] The assembly of the cage unit 2 is completed by controlling the splicing between adjacent sections of the steel cage. This involves splicing the sleeve opening at one end of one section of the cage with the shrinking head of the adjacent section, creating a non-contact overlap. The segmented assembly method better accommodates the segmented installation of the steel pipe 1, facilitating subsequent installation. The length of the cage unit 2 is the length of the corresponding steel pipe 1 segment plus the length of the splicing section between the shrinking head and the splicing interface. The weight of the cage unit 2 is calculated to verify whether the combined weight of the cage unit 2 and the steel pipe 1 exceeds the tower crane's lifting capacity. The maximum weight of the cage unit 2 occurs between L06 and L16. At this point, the steel pipe 1 is 12.6 meters long with an outer diameter of 1500 mm, while the cage unit 2 is 14.2 meters long with an outer diameter of 910 mm, weighing approximately 1.82 tons.

[0029] Among them, the arc-shaped support plate 5 is spliced ​​by at least two arc-shaped plates 51, and a stiffening plate 52 is welded at the joint between adjacent arc-shaped plates 51, and the edge of the stiffening plate 52 is beveled, so that the weld of the arc-shaped plate 51 is smooth; one end of the arc-shaped support plate 5 is fixedly connected to a ring plate 53, and after the arc-shaped support plate 5 is pushed into the steel pipe 1, the ring plate 53 is blocked at the head end of the steel pipe 1; further, both ends of the ring plate 53 are fixedly connected to ear plates 54, and the ear plates 54 are penetrated by connection holes for tying pull ropes.

[0030] The arc support plate 5 formed by splicing the arc plates 51 will form a sliding groove for the sliding of the steel cage in the arc recess. Through the sliding groove, each section of the steel cage can be easily pushed into the steel pipe 1; by arranging the stiffening plate 52 at the splicing seam, the overall strength of the arc support plate 5 can be improved, and the arc support plate 5 can be prevented from cracking and breaking at the splicing seam during use; by arranging the ring plate 53, when the arc support plate 5 is pushed into the steel pipe 1, the ring plate 53 can be tightly attached to the mouth of the steel pipe 1, so that the arc support plate 5 can be completely pushed into the steel pipe 1, that is, the two ends of the arc support plate 5 are flush with the head and tail ends of the steel pipe 1 respectively, realizing automatic calibration; two ear plates 54 are welded on the ring plate 53, which are used when pulling out the arc support plate 5 after installing the steel cage unit 2. Through the connection holes arranged on the ear plates 54, the support plate can be conveniently pulled out of the inside of the steel pipe 1 using tools such as ropes.

[0031] Among them, the steps are also included: after hoisting the steel pipe 1 and the steel cage unit 2 as a whole to the installation site for installation, the steel pipes 1 are welded together, and pouring holes are reserved on the side of the lower end of the steel pipe 1, and concrete is poured through the pouring holes by the jacking method to form a concrete column of the steel pipe 1; high-performance self-compacting concrete is selected as the concrete, and the concrete needs to have high strength, high fluidity, low hydration heat, micro-expansion, high stability and self-compacting properties.

[0032] Beneficial effects of the present invention: The present invention addresses the difficulties in installing a steel cage in an inclined steel pipe 1, determines the idea of ​​prefabricating the steel cage, fixing it to the steel pipe 1, and hoisting it as a whole, clarifies the distance between the steel cage and the inner wall of the steel pipe 1, and proposes a non-contact overlap connection method between each section of the steel cage; during the installation process, the arc-shaped support plate 5 is used to overcome the influence of the bolts 4 in the steel pipe 1, the steel cage is fixed by welding positioning ribs 6 in batches, and the steel cage is hoisted as a whole to install the steel cage in the steel pipe 1, and finally the concrete jacking technology is used to complete the pouring of concrete in the steel pipe 1; this method is technically reliable, can effectively ensure the construction quality of the inclined steel pipe concrete column with internal steel bars, not only saves costs, but also shortens the construction period, and has a good prospect for promotion and application.

[0033] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0034] The present invention has been described in detail above with reference to the embodiments of the accompanying drawings. A person skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention. The scope of protection of the present invention shall be determined by the scope defined in the appended claims.

Claims

1. A method for constructing an inclined steel tube concrete column with internal reinforcement, wherein bolts are provided circumferentially inside the steel tube, characterized in that the steps include: Provide an arc-shaped support plate, the length of which is the same as the length of the steel pipe, and the diameter of which is no larger than the inner diameter of the entire circle of bolts in the steel pipe; Place the steel pipe flat on the ground, then push the curved support plate into the steel pipe and make the two ends of the curved support plate flush with the head and tail ends of the steel pipe respectively, and the outer circumference of the curved support plate rests on the pegs at the bottom of the steel pipe; A steel cage unit is manufactured, wherein the steel cage unit is a segmented structure, and one end of each segment of the steel cage is formed with a shrinking head for inserting into the adjacent segment of the steel cage; and the steel cage unit is pushed into the steel pipe along the arc-shaped support plate; The tail end of the steel cage unit is welded to the tail end of the steel pipe using the first positioning rib, and the head end of the steel cage unit is welded to the first part of the head end of the steel pipe using the second positioning rib, wherein the first part is the part avoiding the arc-shaped support plate; Pull out the arc-shaped supporting plate, and then weld the head end of the steel cage unit and the rest of the head end of the steel pipe to the second positioning rib; Hoisting the steel pipe and steel cage unit as a whole to the installation site for installation; One end of the arc-shaped support plate is fixedly connected to a ring plate; after the arc-shaped support plate is pushed into the steel pipe, the ring plate blocks the head end of the steel pipe; The method also includes the following steps: hoisting the steel pipe and the steel cage unit as a whole to the installation site for installation, welding the steel pipe to connect the steel pipe, reserving a casting hole on the side of the lower end of the steel pipe, and casting concrete through the casting hole by jacking method to form a steel pipe concrete column.

2. The construction method of the inclined steel tube concrete column with internal reinforcement according to claim 1, characterized in that: Each section of the steel cage includes longitudinal bars, which are arranged in a ring. Each section of the steel cage also includes stirrups, which are tied around the outer periphery of the longitudinal bars arranged in a ring.

3. The construction method of an inclined steel tube concrete column with internal steel bars as described in claim 1, wherein each section of the steel cage is formed with a sleeve opening corresponding to one end of the shrinking head, the sleeve opening and the shrinking head are overlapped with each other in a non-contact manner, and the distance between the inner side of the sleeve opening and the outer side of the shrinking head is not greater than one-fifth of the overlap length or 150 mm.

4. The method for constructing an inclined steel tube concrete column with internal reinforcement according to claim 1, wherein: The arc-shaped supporting plate is formed by splicing at least two arc-shaped plates, and a stiffening plate is welded at the joints between adjacent arc-shaped plates.

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