Thin-wall concrete filled steel tubular column with built-in spiral reinforcing steel bar stiffeners and construction method

Abstract

The invention discloses a thin-wall concrete-filled steel tube column with built-in spiral reinforcing steel bar stiffeners and a construction method, the thin-wall concrete-filled steel tube column comprises a thin-wall steel tube column, at least one stiffener is arranged in the thin-wall steel tube column, the stiffener is a spiral reinforcing steel bar, the projection of the spiral reinforcing steel bar in the length direction of the thin-wall steel tube column is octagonal, and the stiffener is arranged in the thin-wall steel tube column. The octagon is provided with long sections and short sections, and the long sections and the short sections are distributed in the circumferential direction of the octagon at intervals. The short section of the spiral steel bar is fixedly connected with the inner side wall of the thin-wall steel pipe column; and the thin-wall steel pipe column is filled with concrete to form the reinforcing steel bar reinforced thin-wall steel pipe concrete column.

Description

Technical Field

[0001] The present invention relates to the technical field of building structures, and in particular to a thin-walled steel tube concrete column with built-in spiral steel reinforcement members and a construction method. Background Art

[0002] Steel tube concrete columns are composed of concrete poured inside steel tubes. This not only makes up for the shortcomings of the two materials, but also gives full play to the advantages of both, making steel tube concrete columns have the advantages of high bearing capacity, good seismic performance, and convenient construction. In order to reduce the thickness of the steel tubes of ordinary steel tube concrete columns and improve the economy of square steel tube concrete columns, thin-walled square steel tube concrete columns appear. However, the local stability problem of thin-walled steel tube concrete columns is prominent, resulting in a weak constraint effect of thin-walled steel tubes on the core concrete. The interaction between the two is poor, and the advantages of their respective materials cannot be fully utilized, resulting in low bearing capacity and poor ductility. For the reinforcement of thin-walled steel tube columns, welding studs, longitudinal stiffening ribs, and constraint rods on the inner wall of the steel tube are currently commonly used reinforcement measures, such as Figure 3 As shown in Figures ac and ac, these reinforcement measures can enhance the interaction between thin-walled steel pipe columns and concrete. However, after actual construction, it was found that these commonly used reinforcement measures in the existing technology are very unfavorable for thin-walled steel pipe columns. Figure 3 As shown in Figure a, welded studs are very easy to penetrate thin-walled steel pipe columns, and the reinforcement effect is poor after actual construction and use. Figure 3 As shown in b, longitudinal stiffening ribs can be set in the steel pipe column, but such longitudinal stiffening ribs need to have sufficient rigidity to meet the reinforcement requirements, so such longitudinal stiffening ribs need to be made very high. At the same time, it is also found in actual construction that when the steel pipe columns are spliced ​​on site, the longitudinal stiffening ribs in the two spliced ​​steel pipe columns cannot be welded, which leads to the discontinuity of longitudinal force transmission and the interruption of force transmission, which in turn causes material waste. In addition, Figure 3 Both a and 3b require the steel pipe to be opened before the internal studs or longitudinal stiffeners can be welded. This means that the studs or longitudinal stiffeners may be welded on two U-shaped steels or two L-shaped steels or four independent steel plates first, and then welded together to form a steel pipe. The welding workload is huge. Figure 3 As shown in c, a restraining rod can also be set in the steel pipe column. Although the restraining effect is good, it is necessary to open holes in the corresponding position of the steel pipe in advance during production. It is not only troublesome to make, but also causes the thin-walled steel pipe column to be weakened. At the same time, the nut of the restraining rod protrudes from the steel pipe, which will increase the additional decoration cost and the reinforcement effect will be adversely affected. Summary of the Invention

[0003] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a thin-walled steel tube concrete column with built-in spiral steel reinforcement and a construction method, so as to solve the problems in the prior art that when reinforcing the thin-walled steel tube column, the thin-walled steel tube column will have an adverse effect, the welding workload is large, the reinforcement effect is poor, and it is easy to cause material waste.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] A thin-walled steel tube concrete column with built-in spiral steel bar reinforcement comprises a thin-walled steel tube column, at least one reinforcement is provided inside the thin-walled steel tube column, the reinforcement is a spiral steel bar, the projection of the spiral steel bar along the length direction of the thin-walled steel tube column is an octagon, the octagon has a long section and a short section, and the long section and the short section are spaced apart along the circumference of the octagon; the short section of the spiral steel bar is fixedly connected to the inner wall of the thin-walled steel tube column; concrete is filled in the thin-walled steel tube column to form the steel bar reinforced thin-walled steel tube concrete column.

[0006] Preferably, the cross-section of the thin-walled steel pipe column is square or rectangular.

[0007] Preferably, the thickness of the thin-walled steel pipe column is 2 to 8 mm, and the cross-sectional width of the thin-walled steel pipe column is 300 to 1100 mm.

[0008] Preferably, the ratio of the width to thickness of the thin-walled steel pipe column is greater than the limit value of 60×(235 / fak) 0.5 .

[0009] The present invention provides a construction method for the above-mentioned thin-walled steel tube concrete column, and the specific steps are as follows:

[0010] Step 1: Obtain a thin-walled steel pipe column through an integrated molding process, place spiral steel bars in the thin-walled steel pipe column, and temporarily fix the spiral steel bars;

[0011] Step 2: Use an automatic welding device to weld and fix the short section of the spiral steel bar to the inner wall of the thin-walled steel pipe column;

[0012] Step 3: pouring concrete into the thin-walled steel tube column so that the concrete completely covers the spiral steel bar to form the thin-walled steel tube concrete column with the built-in spiral steel bar reinforcement.

[0013] Preferably, the thickness of the thin-walled steel pipe column is 2-8 mm, and the ratio of the steel pipe width to the thickness is greater than the limit value of 60×(235 / fak)0.5.

[0014] Preferably, the cross-section of the thin-walled steel pipe column is square or rectangular.

[0015] Preferably, the automatic welding device comprises at least two fixing members I and at least two fixing members II; a plurality of grooves are provided on one side surface of the fixing member I along its length direction, and the positions of the grooves correspond one to one with the positions of the short sections of the spiral steel bars; a track is provided on the other side surface of the fixing member I along its length direction and away from the grooves, and the track is arranged along the length direction of the fixing member I and extends from one end of the fixing member I to the other end; a welding platform is provided above the track, and a plurality of rotating wheels are provided on the side of the welding platform facing the track, and the rotating wheels are engaged with the track, and the welding platform can be moved along the length direction of the track through the rotating wheels Move and stop to be fixed at the target position; a connecting piece is also provided between the welding platforms on the two fixing pieces I, and the two ends of the connecting piece are respectively fixedly connected to the two welding platforms, and the length direction of the connecting piece is consistent with the length direction of the short section of the spiral steel bar; a bracket is provided above the connecting piece, one end of the bracket is slidably connected to the connecting piece; the other end of the bracket is provided with a welding gun that can be moved in the vertical direction by a lifting device; the cross-section of the fixing piece II is U-shaped, and a plurality of magnetic bases are provided at intervals along the length direction inside the closed end of the U-shape, which are used to fix both the fixing piece I and the fixing piece II on the thin-walled steel pipe column.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention changes the stiffener from a zigzag steel bar to a spiral steel bar, and the projection of the spiral steel bar along the length direction of the thin-walled steel pipe column is an octagon, so that its short section is fixedly connected to the inner wall of the thin-walled steel pipe column. This can make the thin-walled steel pipe concrete column exhibit a ductile failure mode under the action of reciprocating loads, that is, the steel pipe first yields and then buckles, and the steel bar is finally pulled to yield or break, avoiding the brittle failure caused by stress concentration at the zigzag steel bar welding point, and can give full play to the plastic properties of the steel to absorb energy, providing time for personnel evacuation and emergency treatment.

[0018] 2. The spiral reinforcement used in this invention provides continuous restraint to the thin-walled steel tubular column, delaying its local buckling. Simultaneously, it enhances the restraint of the thin-walled steel tubular column on the concrete within, strengthening the interaction between the thin-walled steel tubular column and the concrete, thereby improving the strength and ductility of the thin-walled steel tubular concrete column.

[0019] 3. The thin-walled steel pipe column used in the present invention can meet the same width-to-thickness ratio requirements as the prior art when the steel pipe thickness is thin. For example, when the column section width exceeds 1100mm, the thickness of the steel pipe in the prior art needs to be more than 22mm to meet the width-to-thickness ratio requirement, while the present invention only needs 8mm, which helps to reduce the deadweight of the structure, save steel, and expand the application scope of thin-walled steel pipe concrete columns.

[0020] 4. The present invention adopts an integrated molding process to manufacture thin-walled steel pipe columns, which greatly reduces the welding workload, avoids the problem that the spiral steel bars cannot be welded and fixed due to the traditional splicing process, ensures the continuity of longitudinal force transmission, and enables the spiral steel bars to fully play a reinforcing role and reduce material waste; at the same time, a special automatic welding device is designed for this purpose. Through the coordinated work of fixing parts I, fixing parts II, welding platform, servo motor and other components, the short section of spiral steel bar can be accurately welded and fixed to the inner wall of the thin-walled steel pipe column, thereby improving welding quality and construction efficiency, and can adapt to thin-walled steel pipe columns and spiral steel bars of different lengths. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic structural diagram of the thin-walled steel pipe column of the present invention after being connected to the automatic welding device.

[0022] Figure 2 for Figure 1 Schematic diagram of the structure of the automatic welding device in part A.

[0023] Figure 3 This is a structural diagram of a conventional steel pipe column after reinforcement treatment; a is stud reinforcement, b is longitudinal stiffening rib, and c is restraining rod.

[0024] Figure 4 This is a schematic diagram of the structure after the zigzag steel bars are connected to the thin-walled steel pipe column.

[0025] In the figure: stiffener 1, thin-walled steel pipe column 2, fixing part I 3, fixing part II 4, track 5, welding platform 6, runner 7, servo motor I 8, reducer 9, connecting part 10, bracket 11, servo motor II 12, servo motor III 13, welding gun 14, magnetic base 15, vertical section 16. DETAILED DESCRIPTION

[0026] The present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments derived by persons of ordinary skill in the art based on the present invention are within the scope of protection of the present invention.

[0027] 1. A thin-walled steel tube concrete column with built-in spiral steel reinforcement

[0028] The thin-walled steel tube concrete column of the present invention comprises a thin-walled steel tube column 2, such as Figure 1As shown, at least one stiffener 1 is provided inside the thin-walled steel pipe column, and the stiffener is a spiral steel bar, the projection of the spiral steel bar along the length direction of the thin-walled steel pipe column is an octagon, and the octagon has a long section and a short section, and the long section and the short section are distributed at intervals along the circumference of the octagon; the short section of the spiral steel bar is fixedly connected to the inner wall of the thin-walled steel pipe column; concrete is filled in the thin-walled steel pipe column to form the steel bar reinforced thin-walled steel pipe concrete column.

[0029] During the research, the present invention found that the applicant had proposed a reinforcement measure of setting zigzag steel bars in thin-walled steel pipe columns, such as Figure 4As shown, this reinforcement measure can effectively solve a series of adverse technical problems caused by existing reinforcement measures for thin-walled steel pipe columns, and has a good restraining effect. However, after further research, the applicant found that the zigzag steel bar is fixed to the inner wall of the thin-walled steel pipe column by welding. The zigzag steel bar is welded to the inner wall of the thin-walled steel pipe column via vertical section 16. This weld will cause stress concentration when subjected to stress, which is not conducive to load bearing. Moreover, this weld is a weak area and is prone to tearing first under the action of reciprocating loads, and then brittle failure occurs. This failure will precede the buckling of the thin-walled steel pipe. For technicians, this is an undesirable and undesirable failure mode. Because this brittle failure often occurs very suddenly and without warning, as a critical connection point, the sudden failure of the weld will lead to the complete loss of its reinforcement function, which is very likely to immediately cause large-scale buckling of the steel pipe or overall instability of the steel pipe concrete column. In turn, the failure is global and catastrophic, which is difficult to avoid through deformation or early warning measures and often may cause serious safety accidents. Therefore, this is an undesirable and undesirable failure mode. Based on this, the present invention further improves the shape of the stiffener, hoping to produce a ductile failure mode, that is, under the action of reciprocating loads, the steel pipe first yields and then buckles, the weld between the steel bar and the steel pipe has sufficient bearing capacity, the weld is intact, and finally the steel bar is pulled to yield or break. The present invention uses spiral steel bars to replace the original stiffeners. The projection of the spiral steel bars along the length direction of the thin-walled steel pipe column is an octagon. The octagon has a long section and a short section, and the long section and the short section are spaced apart along the circumference of the octagon, so that the short section of the spiral steel bar is welded and fixed to the inner wall of the thin-walled steel pipe column, which can not only strengthen the constraint on the thin-walled steel pipe column, but also enhance the interaction between the thin-walled steel pipe and concrete. When the thin-walled steel pipe concrete column described in the present invention is subjected to a reciprocating load, the steel pipe first yields and then buckles. The weld between the steel bar and the steel pipe has sufficient bearing capacity and the weld is intact. Finally, the steel bar is pulled to yield or break, and the failure mode of the thin-walled steel pipe concrete column is transformed into a ductile failure mode. This is because when the building structure is under a reciprocating load, the ductile failure mode can give full play to the most important mechanical advantage of steel, that is, the steel uses its plastic properties to yield, and then absorbs the energy applied to the building structure by the outside world by generating plastic deformation, providing valuable time for personnel evacuation and emergency measures. In addition, Figure 4 The first step is to weld zigzag steel bars inside two U-shaped steel pipes, and then butt-weld the two U-shaped steel pipes to form a reinforced thin-walled steel pipe column. Compared with the thin-walled steel pipe formed in one step, this method adds two butt welds, which is labor-intensive and prone to thermal deformation. The present invention uses a one-step steel pipe to avoid this problem.

[0030] In some embodiments of the present invention, the thickness of the thin-walled steel pipe column is 2-8 mm, and the ratio of the width to the thickness of the steel pipe is greater than the limit of 60×(235 / fak) 0.5The thin-walled steel tube column described in the present invention is not simply judged by the thickness of the steel tube. In the prior art, the "Code for Design of Composite Structures" stipulates that the cross-sectional size of ordinary rectangular or square steel tube concrete columns should not be less than 400mm, the thickness of the steel tube should not be less than 8mm, and the ratio of the steel tube width to thickness should not exceed the limit of 60×(235 / fak) 0.5 , where fak is the standard value of the steel tube yield strength. In the present invention, the thin-walled steel tube concrete column refers to a steel tube concrete column in which the ratio of the steel tube width to thickness in the column exceeds this limit. Therefore, there are two situations for the thin-walled steel tube column described in the present invention. One is: the steel tube thickness is 2 to 8 mm, preferably 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, or 8 mm, and the corresponding cross-sectional width is 300 to 1100 mm. This can be considered a thin-walled steel tube. The other is: when the cross-sectional width of the column exceeds 1100 mm, it cannot be simply determined by the thickness of the steel tube. This is because in the case of this cross-sectional area, the steel tube thickness in the steel tube concrete column in the prior art needs to reach 22 mm or more to meet the width-to-thickness ratio requirements. However, the steel tube thickness used in the thin-walled steel tube concrete column described in the present invention only needs to reach 8 mm to meet the same width-to-thickness ratio requirements as the prior art. In this way, compared with the steel tube thickness in the prior art, the steel tube used in the present invention can still be considered a thin-walled steel tube.

[0031] 2. A construction method for thin-walled steel tube concrete columns with built-in spiral steel reinforcements

[0032] Step 1: Obtain a thin-walled steel pipe column through an integrated molding process, place spiral steel bars in the thin-walled steel pipe column, and temporarily fix the spiral steel bars;

[0033] Step 2: Use an automatic welding device to weld and fix the short section of the spiral steel bar to the inner wall of the thin-walled steel pipe column;

[0034] Step 3: pouring concrete into the thin-walled steel tube column so that the concrete completely covers the spiral steel bar to form the thin-walled steel tube concrete column with the built-in spiral steel bar reinforcement.

[0035] The present invention is based on actual construction after improving the shape of the reinforcement. During the actual construction, it was found that new technical problems arose when fixing the spiral steel bar in the thin-walled steel pipe column. Since the short section of the spiral steel bar needs to be welded and fixed to the inner wall of the thin-walled steel pipe column, in the early stage of research and development, the present invention adopts a rectangular thin-walled steel pipe column formed by splicing two U-shaped steels. First, a short section of the spiral steel bar is welded in one of the U-shaped steels so that half of the structure of the spiral steel bar can be welded and fixed to the inner wall of one of the U-shaped steels, and then the other U-shaped steel is placed on top of it. Finally, the two U-shaped steels are welded and fixed so that the two U-shaped steels enclose a rectangular thin-walled steel pipe column. However, this results in the other half of the spiral steel bar structure being unable to be welded and fixed to the inside of the other U-shaped steel, which will cause the longitudinal force transmission to be unable to proceed continuously and the longitudinal force transmission to be interrupted. The part of the spiral steel bar that is not welded to the U-shaped steel does not actually play its due role, which not only fails to meet the longitudinal reinforcement needs, but also causes material waste. To this end, the present invention considers improving the thin-walled steel pipe column and the construction method. On the one hand, in order to ensure the integrity of the thin-walled steel pipe column and reduce the influence of the welds when the steel pipe columns are spliced, an integrated molding process is adopted to obtain the thin-walled steel pipe column. This thin-walled steel pipe column is seamless and does not require splicing. Spiral steel bars can be placed directly inside it; on the other hand, in order to enable the short sections on the spiral steel bars to be welded and fixed to the inner wall of the thin-walled steel pipe column, the present invention improves the construction method and construction equipment, and thus the short sections on the spiral steel bars that are in contact with the inner wall of the thin-walled steel pipe column can be welded and fixed to the thin-walled steel pipe column, so that the thin-walled steel pipe column can be continuously constrained, thereby delaying the local buckling performance of the thin-walled steel pipe column, enhancing the restraining effect of the thin-walled steel pipe column on the concrete inside it, and making the interaction between the thin-walled steel pipe column and the concrete stronger, ultimately improving the strength and ductility of the thin-walled steel pipe concrete column, and improving the overall seismic performance.

[0036] In some embodiments of the present invention, the thickness of the thin-walled steel pipe column is 2-8 mm, and the ratio of the steel pipe width to the thickness is greater than the limit value of 60×(235 / fak)0.5.

[0037] In some embodiments of the present invention, the thin-walled steel pipe column has a square or rectangular cross-section, wherein the wall thickness of the thin-walled steel pipe column is 2 to 8 mm, preferably any one of 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, and 8 mm; and the cross-sectional width of the thin-walled steel pipe column is 300 to 1100 mm.

[0038] In some embodiments of the present invention, the interface width of the thin-walled steel pipe column is greater than 1100 mm, and the thickness of the steel pipe wall is greater than 8 mm.

[0039] In some embodiments of the present invention, Figure 1 and 2As shown, the automatic welding device includes at least two fixing parts I 3 and at least two fixing parts II 4. The length directions of the fixing parts I and II are consistent with the length direction of the thin-walled steel pipe column. A plurality of grooves are provided on one side surface of the fixing part I along its length direction. The positions of the grooves correspond one-to-one with the positions of the short sections of the spiral steel bars. When the fixing part I is placed above the spiral steel bars, the grooves can clamp the short sections of the spiral steel bars, thereby temporarily fixing the spiral steel bars and preventing them from being displaced during welding, thereby affecting the welding operation and welding quality. A track 5 is provided on the other side surface of the fixing part I along its length direction and away from the grooves. The track is arranged along the length direction of the fixing part I and extends from one end of the fixing part I to the other end. One end of the track can be set as a closed section as needed. When a thin-walled steel pipe column is long and requires multiple fixtures (I) to be spliced ​​together, the track on the fixtures (I) at both ends of the thin-walled steel pipe column has one closed end and the other open end, which is used for splicing with other fixtures (I). The track formed by the multiple fixtures (I) forms an interconnected track, allowing the welding platform to move on the track formed by the multiple fixtures (I). A welding platform 6 is provided above the track. A rotating wheel 7 is provided on the side of the welding platform facing the track. The rotating wheel engages with the track, and the welding platform can move along the length of the track via the rotating wheel. A servo motor (I) 8 is located on the lower surface of the welding platform, corresponding to a position above the track. The servo motor (I) is fixedly connected to the welding platform, and the drive end of the servo motor (I) is connected to the rotating wheel through a reducer (9). The reducer is a conventional device and can be used to convert the rotational drive of the servo motor (I) drive end into a linear drive. The structure of the reducer is only illustrated here. The reducer includes a reducer housing and a drive rod I. The drive rod I is horizontally disposed, with its ends extending through opposite sides of the reducer housing and then extending from the housing to be fixedly connected to the rotating shaft of the rotating wheel. The axis of the drive rod I coincides with the axis of the rotating wheel, enabling the drive rod I to drive the rotating wheel to rotate about the axis. A servo motor I extends through a side wall of the reducer housing and into the interior of the reducer housing. The drive end of the servo motor I is fixedly connected to a bevel gear I within the reducer housing. The bevel gear I is horizontally disposed and positioned above the drive rod I. The axis of the servo motor I's drive end coincides with the axis of the bevel gear I, enabling the servo motor I's drive end to drive the bevel gear I to rotate about the axis of the bevel gear I. Two bevel gears II are sleeved on the drive rod I. The bevel gears II are fixedly connected to the drive rod I, with their axes coinciding with the axis of the drive rod I, enabling the bevel gears II to rotate about the axis of the drive rod I. The two bevel gears II are respectively located on both sides of the bevel gear I in the horizontal direction, and the bevel gear I is meshed and connected with the bevel gear II.When the drive shaft of servo motor I rotates bevel gear I, it simultaneously drives two bevel gears II to rotate around the axis of drive rod I, thereby driving the rotating wheel to rotate around the axis of drive rod I. Servo motor I can drive the rotating wheel to rotate, causing the welding platform to move along the length of the track and allowing the rotating wheel to stop and be fixed at a certain position on the track. A connector 10 is also provided between the welding platforms on the two fixing members I. The ends of the connector are respectively fixedly connected to the two welding platforms on the two fixing members I, and the length of the connector is consistent with the length of the short section of spiral steel bar. A bracket 11 is provided above the connector, one end of which is slidably connected to the connector, allowing the bracket to slide along the length of the connector. A servo motor II is provided on the welding platform, which is fixedly connected to the welding platform. The drive end of the servo motor II is fixedly connected to the bracket via a transmission member. The transmission member is a conventional member in the prior art that can convert the rotational drive of the servo motor II drive end into a linear drive, allowing the servo motor II to drive the bracket to move along the length of the connector and allow the bracket to stop and be fixed at a certain position on the connector. Here, an example is given to illustrate the structure of the transmission component. The transmission component includes a screw rod I with a thread. One end of the screw rod I is fixedly connected to the driving end of the servo motor II, and the axis of the screw rod I coincides with the axis of the driving end of the servo motor II, so that the servo motor II can drive the screw rod I to rotate around the axis of the screw rod I; the length direction of the driving end of the servo motor II and the length direction of the screw rod I are consistent with the length direction of the connecting member. A threaded hole is provided on the bracket, and the screw rod I is connected to the threaded hole by a thread. When the driving end of the servo motor II drives the screw rod I to rotate, the screw rod I can drive the bracket to move along the length direction of the connecting member to the target position through the thread of the threaded hole and be fixed at the target position. The other end of the bracket is provided with a welding gun 14 that can be moved in the vertical direction by a lifting device. The lifting device can also adopt a conventional lifting device that can realize the welding gun moving up and down in the vertical direction. For example, the lifting device includes a servo motor III, which is fixedly connected to the other end of the bracket. The driving end of the servo motor III is arranged in a vertical direction, and a screw II is provided on the driving end of the servo motor III. The axis of the screw II coincides with the axis of the driving end of the servo motor III, and one end of the screw II is fixedly connected to the driving end of the servo motor III. The lifting device also includes a sleeve, which is fixed to the outside of the welding gun and has a connecting hole provided therein. The connecting hole is provided with a thread, and the screw II is threadedly connected to the connecting hole. When the driving end of the servo motor III rotates, it can drive the screw II to rotate, thereby moving the welding gun up and down in the vertical direction. The cross-section of the fixing member II is U-shaped, and a plurality of magnetic bases 15 are provided inside the closed end of the U-shape along its length.In actual use, all components involved in this invention are factory-customized in batches using steel, ensuring that each component meets the construction design requirements. The fixing member II is positioned on the outer wall of the thin-walled steel pipe column, corresponding to the position of the fixing member I. The magnetic base on the fixing member II secures the fixing member I to the interior of the thin-walled steel pipe column, simultaneously securing the spiral rebar within the thin-walled steel pipe column. The welding angle of the welding gun can be pre-set without affecting its movement.

[0040] Working process: First, place two fixings I above the short section of spiral rebar, so that the slots on fixings I can grip the short section of spiral rebar, temporarily securing fixings I inside the spiral rebar. Then, place the spiral rebar and fixings I together into the thin-walled steel pipe column and adjust their positions. After adjustment, place fixings II outside the thin-walled steel pipe column, corresponding to the position of fixings I. Use magnetic bases to temporarily secure fixings I and the spiral rebar inside the thin-walled steel pipe column to prevent them from moving during welding. Subsequently, the controller activates servo motor I, which drives the welding platform to move above the short segment of spiral rebar and stop there. Servo motor III is then activated, driving the welding gun down to the point where the short segment of spiral rebar contacts the thin-walled steel pipe column and needs to be welded. Finally, servo motor II and the welding gun are activated simultaneously. While the welding gun welds the short segment of spiral rebar to the thin-walled steel pipe column, servo motor II drives the welding gun to move along the length of the short segment of spiral rebar a distance that matches the welding length of the welding gun. After welding is completed, the welding gun is turned off, servo motor II drives the welding gun to its original position, and servo motor III drives the welding gun upward to its original position. Servo motor I is then activated, driving the welding platform to the next location where the short segment of spiral rebar needs to be welded. This process is repeated until the short segment of spiral rebar is welded to the inner wall of one side of the thin-walled steel pipe column. Fixtures I and II are then removed to facilitate welding on the other side. Because the spiral rebar is manufactured in a modular factory, the distance between adjacent short segments along the length of the thin-walled steel pipe column can be kept constant. By setting the parameters of their controllers, servo motors I, II, and III can drive the welding platform and welding guns to the target positions for welding. The automatic welding device can have multiple welding guns, allowing for the welding of multiple short segments of spiral rebar, improving welding efficiency.

[0041] In some embodiments of the present invention, the number of welding platforms may be one, and multiple welding guns may be arranged on one welding platform to weld multiple short sections of spiral steel bars at the same time.

[0042] In some embodiments of the present invention, the welding material is bonded to the spiral steel bar at the location where it is to be welded to the thin-walled steel pipe column using an adhesive to prevent the welding material from moving during the welding process, thereby affecting the weld quality. Alternatively, a welding gun capable of automatic wire feeding may be used for welding.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the technical solutions. Those skilled in the art should understand that modifications or equivalent replacements of the technical solutions of the present invention that do not depart from the purpose and scope of the technical solutions of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A thin-walled steel tube concrete column with built-in spiral steel reinforcement, characterized in that: The invention comprises a thin-walled steel pipe column (2), wherein at least one stiffening member (1) is provided inside the thin-walled steel pipe column, wherein the stiffening member is a spiral steel bar, wherein the projection of the spiral steel bar along the length direction of the thin-walled steel pipe column is an octagon, wherein the octagon has a long section and a short section, and the long section and the short section are spaced apart along the circumference of the octagon; the short section of the spiral steel bar is fixedly connected to the inner wall of the thin-walled steel pipe column; and concrete is filled in the thin-walled steel pipe column to form the steel bar reinforced thin-walled steel pipe concrete column.

2. The thin-walled steel tube concrete column according to claim 1, characterized in that: The cross section of the thin-walled steel pipe column is square or rectangular.

3. The thin-walled steel tube concrete column according to claim 2, characterized in that: The thickness of the thin-walled steel pipe column is 2 to 8 mm, and the cross-sectional width of the thin-walled steel pipe column is 300 to 1100 mm.

4. The thin-walled steel tube concrete column according to claim 2, characterized in that: The ratio of the width to thickness of the thin-walled steel pipe column is greater than the limit of 60×(235 / fak) 0.5 .

5. A construction method for a thin-walled steel tube concrete column according to any one of claims 1 to 4, characterized in that: The specific steps are as follows: Step 1: Obtain a thin-walled steel pipe column through an integrated molding process, place a spiral steel bar in the thin-walled steel pipe column, and secure the spiral steel bar; Step 2: Use an automatic welding device to weld the short section of the spiral steel bar to the inner wall of the thin-walled steel pipe column; Step 3: pouring concrete into the thin-walled steel tube column so that the concrete completely covers the spiral steel bar to form the thin-walled steel tube concrete column with the built-in spiral steel bar reinforcement.

6. The construction method according to claim 5, characterized in that: The thickness of the thin-walled steel pipe column is 2-8 mm, and the ratio of the steel pipe width to thickness is greater than the limit of 60×(235 / fak) 0.5 .

7. The construction method according to claim 5, characterized in that: The cross section of the thin-walled steel pipe column is square or rectangular.

8. The construction method according to claim 5, characterized in that: The automatic welding device comprises at least two fixing members I (3) and at least two fixing members II (4); a plurality of grooves are provided on one side surface of the fixing member I along its length direction, and the positions of the grooves correspond one to one with the positions of the short sections of the spiral steel bars; a track (5) is provided on the other side surface of the fixing member I along its length direction and away from the grooves, and the track is arranged along the length direction of the fixing member I and extends from one end of the fixing member I to the other end; a welding platform (6) is provided above the track, and a plurality of rotating wheels (7) are provided on the side of the welding platform facing the track, and the rotating wheels are engaged with the track, and the welding platform can move along the length direction of the track and Stop and fix at the target position; a connecting piece (10) is also provided between the welding platforms on the two fixing pieces I, and the two ends of the connecting piece are fixedly connected to the two welding platforms respectively, and the length direction of the connecting piece is consistent with the length direction of the short section of the spiral steel bar; a bracket (11) is provided above the connecting piece, one end of the bracket is slidably connected to the connecting piece; the other end of the bracket is provided with a welding gun (14) that can be moved in the vertical direction by a lifting device; the cross-section of the fixing piece II is U-shaped, and a plurality of magnetic bases (15) are provided at intervals along the length direction inside the closed end of the U-shape, which are used to fix both the fixing piece I and the fixing piece II on the thin-walled steel pipe column.

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