Construction method of square-cased circular steel tube reinforced concrete columns

Abstract

The present invention relates to a construction method for a square-sheathed round steel tube reinforced concrete column, comprising the following steps: concrete foundation pedestal construction, steel tube reinforced column shaping and hoisting, steel tube reinforced column positioning and installation, steel tube reinforced column peripheral reinforcement skeleton installation, steel tube reinforced column peripheral square column formwork installation, outer hoop slurry collection device installation, high-throw self-compacting steel tube reinforced concrete column internal and external integrated pouring, and concrete curing. The beneficial effects of the present invention are: precise positioning and installation of the steel tube reinforced column are achieved through annular grooves, steel plate with positioning rings, positioning ribs, leveling bubbles and other devices; high-throw self-compacting concrete technology is used to achieve integrated, rapid, and high-quality pouring of concrete inside and outside the steel tube reinforced column; steel formwork provided with corbels and self-adhesive rubber strips is used as the formwork system for the concrete outside the tube, thereby improving the stability and sealing of the formwork; and the outer hoop slurry collection technology is used to achieve rapid collection and reuse of concrete slurry.

Description

Technical Field

[0001] The present invention relates to the technical field of housing construction, and in particular to the construction of square-cased round steel tube reinforced concrete columns. The invention is particularly suitable for the construction of steel tube reinforced concrete columns with a diameter of ≥350 mm and a height of ≥4 m in high-rise and super-high-rise building structures. Background Art

[0002] Steel structures are increasingly being adopted for their advantages, including short construction times, ease of construction, energy conservation, environmental protection, earthquake resistance, industrialized production, and the concept of a circular economy. Building structures are gradually shifting from traditional reinforced concrete to a combination of steel and reinforced concrete. Concrete-filled steel tubular structures are composite structures that fully utilize material properties, offering excellent load-bearing performance, material savings, and ease of construction. In recent years, due to their high load-bearing capacity, superior earthquake resistance, ease of construction, and excellent fire resistance, they have been widely used in various fields of engineering construction, including housing construction and metallurgy. Their unique characteristics are particularly evident in high-rise buildings.

[0003] The core concrete within the steel tube is often constructed with a slightly expansive concrete type. This serves to fill the gaps left by concrete shrinkage and to ensure a better connection and synergy between the steel tube and concrete. Excessive slump in this type of concrete can lead to segregation. However, a smaller slump increases pumping pressure, so the slump should be maintained between 120 and 180 mm. With the development of technology, self-compacting concrete technology has emerged, and some underground concrete-filled steel tube columns are often constructed with this new technology. High-drop pouring and pump-and-lift methods are commonly used for core concrete pouring. Other methods include conduit pouring and manual, staged pouring. However, compared to simple steel and concrete structures, concrete-filled steel tube columns are more complex to construct. This is particularly true for square-in-round steel tube reinforced concrete columns, which appear square in appearance but contain steel tubes. Key challenges lie in their positioning and installation, formwork systems, the risk of voids during pouring, and maintenance. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a construction method for a square-in-round steel tube reinforced concrete column.

[0005] The construction method of the square-in-round steel tube reinforced concrete column comprises the following steps:

[0006] Step 1: Excavate the foundation cap area, reserve an annular groove in the center of the steel tube reinforced concrete column, reserve a grouting groove on one side of the outer periphery of the designed position of the steel tube reinforced concrete column, embed U-shaped steel pipes and column foot bolts, tie the foundation cap steel bars, pour concrete, and install a steel plate with a positioning ring in the annular groove;

[0007] Step 2: Make a steel pipe rigid column. A positioning rib is provided at the bottom of the steel pipe rigid column through the column base plate; and a grout overflow vent is provided on the pipe wall;

[0008] Step 3: Paste the longitudinal and transverse level bubbles on the column base plate; then vertically hoist the steel pipe rigid column and make fine adjustments using double nuts;

[0009] Step 4: Tie the steel reinforcement skeleton of the concrete outside the pipe, assemble the steel formwork and set the corbels and self-adhesive rubber strips at the bottom of the steel formwork;

[0010] Step 5: Hoist the outer hoop slurry collection device so that the collection tank is placed around the top of the steel formwork;

[0011] Step 6: Insert the concrete conduit into the steel pipe rigid column and start pouring self-compacting concrete in layers. The concrete and air in the pipe flow into the annular groove through the overflow slurry exhaust hole until it is flush with the foundation cap. Continue pouring concrete at high speed until the slurry flows into the collection tank.

[0012] Step 7: Remove the outer hoop slurry collection device, install the diversion rain cover, and cure the concrete.

[0013] Preferably, in step 1: the diameter of the annular groove is between the diameter of the steel pipe stiffening column and the outer size of the concrete outside the pipe; the inner pipe opening of the U-shaped steel pipe is located at 1 / 2 of the radius from the center of the annular groove, and the outer pipe opening is located at the center of the overflow groove. At the same time, the height of the inner pipe opening is flush with the foundation cap, and the height of the outer pipe opening is 3 to 5 cm lower than the foundation cap; embedded steel bars are vertically installed around the annular groove, and the top of the embedded steel bars is exposed to the foundation cap; column foot bolts are fixed at the designed position of the steel pipe stiffening column positioning rib plate;

[0014] After the initial setting of the concrete and before the final setting, a steel plate strip positioning ring is installed on the surface of the annular groove. The steel plate strip positioning ring is provided with a notch. The centers of the annular groove and the steel plate strip positioning ring are aligned, and the axis of the notch is radially aligned with the column base bolt. The outer diameter of the steel plate strip positioning ring is smaller than the annular groove, and the inner diameter is consistent with the column base plate of the steel pipe rigid column. The shape and size of the notch are consistent with the positioning ribs of the steel pipe rigid column, and are arranged in a ring-shaped symmetrical manner.

[0015] Preferably, in step two: the steel pipe rigid column includes a pipe wall, overflow vent holes, connecting ribs, inner partitions, column top plates, column base plates, positioning ribs and ear plates, wherein the connecting ribs are symmetrically welded to the outside of the pipe wall, and the annular inner partitions are evenly welded to the inside of the pipe wall in lanes; a column top plate is provided at the upper end of the steel pipe rigid column, the column top plate shrinks into the pipe and is symmetrically provided with four screw holes; the column base plate expands outward from the pipe, and the column base plate is symmetrically connected to the four positioning ribs.

[0016] Preferably, in step three: the longitudinal level bubble and the transverse level bubble are long strips and are respectively installed at the longitudinal and transverse positions of the column base plate; the steel pipe rigid column is vertically lifted and dropped so that the through holes of the positioning ribs pass through the column base bolts embedded in step one until they coincide with the gaps of the steel plate with positioning rings; then, gaskets and double nuts are installed in sequence at the column base bolts, and the double nuts are tightened to position the steel pipe rigid column.

[0017] Preferably, in step four: the steel reinforcement skeleton of the concrete outside the pipe includes main reinforcement and stirrups; wherein the main reinforcement located outside the annular groove is welded to the embedded reinforcement; and the steel formwork is fastened and formed using tension bolts on all sides.

[0018] Preferably, in step five: the outer hoop slurry collecting device also includes a guide plate, fixing bolts, a wall panel, a bolt groove, a slurry discharge hole and a conduit; the slurry discharge hole and the conduit are arranged at the bottom of the collection tank; the guide plate and the steel formwork are flush in height; the wall panel fits the outer side of the steel formwork, and the wall panel is symmetrically provided with multiple bolt grooves; the outer hoop slurry collecting device is slid up and down along the bolt groove by the fixing bolts, and is finally supported on the horizontal back rib of the steel formwork, and the fixing bolts are tightened to completely fix the outer hoop slurry collecting device; glass glue is filled between the wall panel and the steel formwork.

[0019] Preferably, in step six: before pouring, a layer of cement mortar with the same strength as the self-compacting concrete and a thickness of 100 to 200 mm is laid on the bottom; the lower end of the concrete conduit opening is greater than or equal to 4 meters above the structural surface, and when pouring concrete in the pipe, part of the air in the steel pipe stiffening column is discharged to the outside through the U-shaped steel pipe;

[0020] When concrete continues to flow out of the outer mouth of the U-shaped steel pipe into the overflow groove, it indicates that the height of the concrete in the pipe is now flush with the foundation pedestal. It pauses for a period of time, and the length of the pause time is less than the initial setting time, until the concrete inside the pipe and the concrete outside the pipe within the annular groove are fully bonded with the inner partition, connecting reinforcement, column base plate and main reinforcement. The outer mouth of the U-shaped steel pipe is tightened and sealed with a cap nut; then the overflow groove is filled and smoothed with expansive concrete. The strength of the expansive concrete is higher than the concrete strength of the foundation pedestal.

[0021] Preferably, in step six: after the height of the concrete in the tube is flush with the foundation cap, the overflow slurry tank is first filled and smoothed, and then the high-throw concrete pouring is continued; when the concrete is poured to the designed height of the steel tube reinforced concrete column, the concrete in the tube and the concrete outside the tube both reach the maximum height; the self-compacting concrete drop height is reduced until the slurry is collected in the collection tank of the outer hoop slurry collection device through the guide plate;

[0022] When the floating slurry is excessive, the floating slurry is discharged and collected through the slurry discharge holes and the conduit at the bottom of the collecting tank.

[0023] Preferably, in step seven: the bottom of the diversion rain shield is flush and the top is umbrella-shaped, and the coverage area of the diversion rain shield is larger than the steel tube rigid concrete column; the diversion rain shield is installed and fixed on the top of the steel tube rigid concrete column through the screw holes of the top plate of the steel tube rigid column; the diversion rain shield also includes a hanging ring and a nut; the nut is consistent with the screw hole of the column top plate.

[0024] A square-in-round steel tube reinforced concrete column is obtained by any of the above methods.

[0025] The beneficial effects of the present invention are:

[0026] 1) The present invention is based on the precise pre-embedding technology of column foot bolts with steel plates and positioning rings. It realizes the precise positioning and installation of steel tube rigid columns through annular grooves, steel plates with positioning rings, positioning ribs, spirit levels and other devices. Compared with traditional technologies, it reduces the number of column foot bolts installed and improves the connection performance between the steel tube rigid columns and the pedestals.

[0027] 2) The present invention realizes the integrated, rapid, and high-quality pouring of concrete inside and outside the steel tube rigid column by setting overflow vent holes, U-shaped steel pipes and other devices and adopting high-throw self-compacting concrete technology, thus avoiding the problem of concrete voiding.

[0028] 3) The present invention adopts a steel formwork with corbels and self-adhesive rubber strips as the formwork system for the concrete outside the pipe, which improves the stability and sealing of the formwork and avoids leakage and overflow of self-compacting concrete during the pouring process due to its easy flow characteristics.

[0029] 4) The present invention adopts outer hoop slurry collection technology to achieve rapid collection and reuse of concrete slurry, avoiding the overflow of slurry and pollution of formwork and ground in traditional technology, and eliminating the need for subsequent roughening to remove surface slurry.

[0030] 5) The present invention adopts diversion and rain protection technology to avoid the influence of rainwater soaking on the casting and curing quality of steel tube reinforced concrete columns, which helps to improve their molding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a transverse cross-section diagram of the concrete foundation cap construction;

[0032] Figure 2 It is a structural diagram of a steel plate with a positioning ring;

[0033] Figure 3 This is a cross-sectional view of the outer square column formwork of the steel tube rigid column after installation;

[0034] Figure 4 This is a top view of part of the structure after the outer square column formwork of the steel tube rigid column is installed;

[0035] Figure 5is a cross-sectional view of the outer hoop slurry collection device;

[0036] Figure 6 is a top view of the outer hoop slurry collection device;

[0037] Figure 7 This is a cross-sectional view of the high-throw self-compacting steel tube reinforced concrete column during its internal and external integrated pouring;

[0038] Figure 8 This is a schematic diagram of the installation of the diversion rain cover.

[0039] Explanation of reference numerals: 1-foundation pedestal; 2-steel tube reinforced concrete column; 3-steel tube reinforced column; 4-concrete inside the tube; 5-concrete outside the tube; 6-annular groove; 7-overflow groove; 8-U-shaped steel tube; 9-inner tube opening; 10-outer tube opening; 11-embedded steel bar; 12-positioning rib plate; 13-column foot bolt; 14-notch; 15-steel plate with positioning ring; 16-tube wall; 17-overflow slurry exhaust hole; 18-connecting rib; 19-inner partition; 20-column top plate; 21-column foot plate; 22-ear plate; 23-screw hole; 24-longitudinal 1-Vertical level bubble; 25-Horizontal level bubble; 26-Gasket; 27-Double nut; 28-Main reinforcement; 29-Stirrups; 30-Corner; 31-Self-adhesive rubber strip; 32-Steel formwork; 33-Outer hoop slurry collection device; 34-Deflector; 35-Retaining bolt; 36-Horizontal back rib; 37-Conduit port; 38-Cap nut; 39-Expanding concrete; 40-Slurry; 41-Collection trough; 42-Diversion rain cover; 43-Wall panel; 44-Bolt channel; 45-Drain hole; 46-Conduit; 47-Lifting ring; 48-Nut. DETAILED DESCRIPTION

[0040] The present invention will be further described below with reference to the following examples. The following examples are provided only to facilitate understanding of the present invention. It should be noted that, without departing from the principles of the present invention, it is possible for a person skilled in the art to make various modifications to the present invention, and such improvements and modifications fall within the scope of the claims of the present invention.

[0041] Example 1

[0042] As an example, Figures 1 to 8 As shown, a construction method of a square-in-round steel tube reinforced concrete column includes the following steps:

[0043] Step 1: Construction of concrete foundation cap

[0044] Excavate the foundation cap area, compact and level the base, mark the casting elevation line, and cast the cushion layer with plain concrete. When tying the reinforcement of the foundation cap 1, the steel tube reinforced concrete column 2 is mainly composed of the steel tube reinforced column 3, the concrete inside the tube 4, and the concrete outside the tube 5. The steel plate with a positioning ring is used to accurately embed the column foot bolts:

[0045] As attached Figure 1 To the attached Figure 4 As shown, an annular groove 6 is reserved at the center of the design position of the steel tube reinforced concrete column 2, and the diameter of the annular groove 6 is between the diameter of the steel tube reinforced concrete column 3 and the outer size of the concrete outside the tube 5; a grouting groove 7 is reserved on the outer side of the design position of the steel tube reinforced concrete column 2, and a U-shaped steel pipe 8 is embedded so that its inner pipe mouth 9 is located at 1 / 2 radius from the center of the annular groove 6, and the outer pipe mouth 10 is located at the center of the grouting groove 7, while ensuring that the height of the inner pipe mouth 9 is flush with the foundation pedestal 1, and the height of the outer pipe mouth 10 is slightly lower than the foundation pedestal 13 to 5 cm; in addition, a number of embedded steel bars 11 are vertically installed around the annular groove 6, with an exposed length of not less than 10 cm; column foot bolts 13 are embedded at the design position of the steel tube reinforced column positioning rib 12.

[0046] After the reinforcement is tied and all embedded parts are installed, the foundation cap concrete is poured and compacted manually with a vibrator. After the concrete has initially set but before final setting, a steel plate with a positioning ring 15 containing a notch 14 is installed on the surface of the annular groove 6. While ensuring center alignment, the axis of the notch 14 is adjusted to align radially with the column foot bolt 13. The outer diameter of the steel plate with a positioning ring 15 is slightly smaller than the annular groove 6, and its inner diameter is consistent with the column foot plate 21 of the steel tube rigid column 3. The shape and size of the notch 14 match the positioning ribs 12 of the steel tube rigid column 3, and four notches are provided in a circular, symmetrical pattern. The diameter of the U-shaped steel pipe 8 should be at least three times the maximum particle size of the coarse aggregate in the self-compacting concrete to avoid clogging.

[0047] Finally, water and cover for maintenance.

[0048] Step 2: Forming and hoisting of steel pipe rigid columns

[0049] As attached Figure 3 To the attached Figure 4As shown, according to the design drawings, a steel tube rigid column 3 is manufactured, including a tube wall 16, grout vents 17, connecting ribs 18, inner partitions 19, column top plates 20, column base plates 21, positioning ribs 12, and ear plates 22. The connecting ribs 18 are symmetrically and evenly welded to the outside of the tube wall 16, the grout vents 17 evenly penetrate the tube wall 16, and the annular inner partitions 19 are evenly welded to the inside of the tube wall 16 in lanes. The column top plate 20 and column base plates 21 are respectively arranged at the upper and lower ends of the steel tube rigid column 3. The former shrinks inwardly and is symmetrically provided with four non-through screw holes 23, while the latter expands outwardly and is symmetrically provided with four positioning ribs 12. Finally, ear plates 22 are symmetrically welded to the upper end of the steel tube rigid column 3 for hoisting. Once the steel tube rigid column's tube wall verticality, column base plate flatness, structural strength and other indicators meet the design requirements, it is shipped out of the factory.

[0050] Step 3: Positioning and installation of steel pipe rigid columns

[0051] After the steel pipe stiffening column 3 is transported to the site, the steel pipe stiffening column precise positioning and installation technology is adopted:

[0052] As attached Figure 3 To the attached Figure 4 As shown, first, a longitudinal level bubble 24 and a transverse level bubble 25 are horizontally pasted on the longitudinal and transverse positions of the column base plate 21 respectively; the longitudinal level bubble 24 and the transverse level bubble 25 are long strips, and their installation axes are vertical and parallel respectively. Then, the steel pipe rigid column 3 is vertically hoisted, and the orientation is adjusted and slowly dropped, so that the four positioning ribs 12 through the holes pass through the pre-buried column base bolts 13 until they fall to the ground and match the gaps of the steel plate belt positioning ring 15; secondly, the gaskets 26 and double nuts 27 are installed in sequence at the column base bolts 13, and the double nuts 27 are preliminarily tightened to position the steel pipe rigid column; finally, the steel pipe rigid column 3 is fine-tuned by further adjusting the tightness of the four double nuts 27 until the bubbles of the longitudinal level bubble 24 and the transverse level bubble 25 are kept in the center, ensuring that the verticality and flatness of the steel pipe rigid column meet the requirements.

[0053] Step 4: Installation of steel reinforcement skeleton around steel pipe rigid column

[0054] As attached Figure 4 As shown, according to the design requirements of the steel tube reinforced concrete column structure, a steel skeleton is tied within the structure range of the outer concrete 5 of the tube, mainly including main bars 28 and stirrups 29. Among them, the main bars located around the annular groove 6 are welded to the embedded steel bars 11.

[0055] Step 5: Install the outer square column formwork of the steel pipe rigid column

[0056] As attached Figure 3 To the attached Figure 4As shown, after the steel tube rigid column's outer reinforcement skeleton is installed, a steel formwork 32 equipped with corbels 30 and self-adhesive rubber strips 31 is sequentially assembled to serve as the formwork system for the concrete 5 outside the tube. The self-adhesive rubber strips 31, positioned at the bottom of the steel formwork 32, compress under their own weight, effectively ensuring the seal at the bottom of the formwork system and preventing leakage or spillage of the self-compacting concrete during pouring. Furthermore, the self-adhesive rubber strips 31 are relatively thin and do not affect the appearance of the concrete at the column base. The steel formwork is supported at the bottom by welded corbels 30 and secured with tension bolts around the perimeter.

[0057] Step 6: Install the outer hoop slurry collection device

[0058] As attached Figure 5 To the attached Figure 7 As shown, the outer hoop slurry collection device 33 is hoisted and completely inserted into the formwork system. When the guide plate 34 is flush with the steel formwork 32, the retaining bolts 35 are slid to support it on the horizontal back ribs 36 of the steel formwork 32, and the bolts are tightened to completely secure the outer hoop slurry collection device 33. The outer hoop slurry collection device 33 also includes a wall panel 43, bolt channels 44, slurry discharge holes 45, and a conduit 46. The wall panel 43 is symmetrically provided with multiple bolt channels 44, along which the retaining bolts 35 can slide up and down. The wall panel 43 is tightly attached to the outside of the steel formwork 32, and the gap between the wall panel 43 and the steel formwork 32 is filled with glass glue.

[0059] Step 7: Integrated pouring of high-throw self-compacting steel tube reinforced concrete columns inside and outside

[0060] Before pouring, lay a layer of cement mortar with the same strength as the self-compacting concrete and a thickness of 100 to 200 mm at the bottom to prevent the coarse aggregate freely dropped from a height from bouncing and causing segregation.

[0061] During pouring, the concrete conduit port 37 is extended into the steel tube rigid column 3, and the lower end of the conduit port is kept at a height of not less than 4m from the structural surface, and the self-compacting concrete is started to be thrown in layers. At this time, the concrete 4 and air in the steel tube rigid column 3 are diverted into the annular groove 6 through the overflow exhaust hole 17, and at the same time, part of the air in the steel tube rigid column 3 is discharged to the outside through the U-shaped steel pipe 8.

[0062] Based on the principle of communicating vessels, when a large amount of concrete suddenly flows out from the outer pipe mouth 10 of the U-shaped steel pipe 8 to the overflow groove 7, it indicates that the height of the concrete in the pipe is now flush with the foundation pedestal 1. The pause period does not exceed the initial setting time. The inner pipe concrete 4 and the outer pipe concrete 5 within the range of the annular groove 6 are fully bonded with the inner partition 19, connecting reinforcement 18, column base plate 21, main reinforcement 28 and other structures. The outer pipe mouth 10 of the U-shaped steel pipe 8 is tightened and sealed with a cover nut 38, and the overflow groove 7 is filled and smoothed with expansive concrete 39 with a strength one grade higher than that of the foundation pedestal concrete.

[0063] As attached Figure 5 As shown, continue to cast concrete at a high altitude. When the concrete is cast to the designed height of the steel tube reinforced concrete column 2, the concrete 4 inside the tube and the concrete 5 outside the tube both reach the maximum height. Lower the height of the self-compacting concrete casting and cast it for a short period of time until the concrete slurry 40 is collected in the collection tank 41 of the outer hoop slurry collection device 33 through the guide plate 34 as shown by the arrow in the figure, so as to avoid the slurry overflowing and contaminating the formwork and the ground during traditional casting.

[0064] When the floating slurry 40 is excessive, it can be discharged and collected through the slurry discharge holes 45 and the conduit 46 .

[0065] Step 8: Concrete Curing

[0066] The outer hoop slurry collecting device 33 is removed and the slurry 40 is recovered and reused.

[0067] As attached Figure 8 As shown, the diversion rain shield 42 is hoisted and fixed to the top of the structure through the screw holes 23 in the top plate 20 of the steel tube reinforced column 3. The diversion rain shield 42 has a flush bottom and an umbrella-shaped top, covering an area slightly larger than the steel tube reinforced concrete column 2. The diversion rain shield 42 also includes a lifting ring 47 and a nut 48 for hoisting and fixing, respectively. The nut 48 completely matches the screw hole 23 in the top plate 20.

[0068] According to seasonal and other environmental factors, the concrete is maintained with thermal insulation and moisture retention.

[0069] Example 2

[0070] According to the construction method of a square-in-round steel tube reinforced concrete column provided in Example 1, the obtained square-in-round steel tube reinforced concrete column includes a concrete foundation cap 1, a steel tube concrete column 2, an annular groove 6, an overflow groove 7, a pre-buried U-shaped steel pipe 8, pre-buried steel bars 11, a column foot bolt 13, and a steel plate with a positioning ring 15. The steel tube concrete column 2 is composed of a steel tube column 3, concrete inside the tube 4, and concrete outside the tube 5. The steel tube column 3 also includes a tube wall 16, an overflow slurry exhaust hole 17, a connecting rib 18, an inner partition 19, a column top plate 20, a column foot plate 21, a positioning rib plate 12, an ear plate 22, and other structures. Among them, the connecting ribs 18 are symmetrically and evenly welded to the outside of the pipe wall 16, the overflow exhaust holes 17 are evenly penetrated through the pipe wall 16, and the annular inner partition 19 is evenly welded to the inside of the pipe wall 16 in lanes; the column top plate 20 and the column base plate 21 are respectively arranged at the upper and lower ends of the steel pipe column 3, the former shrinks into the pipe and is symmetrically provided with four non-through screw holes 23, and the latter expands outward from the pipe and is symmetrically provided with four positioning ribs 12.

[0071] The annular groove 6 is reserved at the center of the designed position of the steel tube concrete column 2 in the concrete foundation cap 1, and its diameter is between the diameter of the steel tube column 3 and the outer size of the concrete outside the tube 5.

[0072] The overflow groove 7 is reserved outside the design position of the steel tube concrete column 2 in the concrete foundation pedestal 1, the inner pipe mouth 9 of the embedded U-shaped steel pipe 8 is located at 1 / 2 radius from the center of the annular groove 6, and the outer pipe mouth 10 is located at the center of the overflow groove 7, and the height of the inner pipe mouth 9 is flush with the concrete foundation pedestal 1, and the height of the outer pipe mouth 10 is slightly lower than the concrete foundation pedestal 1.

[0073] The embedded steel bars 11 are vertically installed around the annular groove 6 , with an exposed length of not less than 10 cm; the column foot bolts 13 are embedded in the designed position of the positioning rib 12 .

[0074] The outer diameter of the steel plate belt positioning ring 15 is slightly smaller than the annular groove 6, and the inner diameter is consistent with the column base plate 21 of the steel pipe column 3; the shape and size of the notch 14 are consistent with the positioning rib 12 of the steel pipe column 3, and four notches 14 are symmetrically arranged in a ring shape.

[0075] Several vials are also provided on the column base plate 21 , including a longitudinal vial 24 and a transverse vial 25 .

Claims

1. The construction method of square-cased round steel tube reinforced concrete column is characterized by: The following steps are involved: Step 1: excavate the foundation pedestal area, reserve an annular groove (6) in the center of the steel tube reinforced concrete column (2), reserve an overflow groove (7) on the outer side of the designed position of the steel tube reinforced concrete column (2), embed U-shaped steel pipes (8) and column foot bolts (13), tie the steel bars of the foundation pedestal (1), pour concrete, and install a steel plate with a positioning ring (15) in the annular groove (6); Step 2: Make a steel pipe rigid column (3), and provide a positioning rib (12) at the bottom end of the steel pipe rigid column (3) through a column base plate (21); and provide a grout overflow vent (17) on the pipe wall (16); Step 3: Paste the longitudinal level bubble (24) and the transverse level bubble (25) on the column base plate (21); then vertically hoist the steel pipe rigid column (3) and perform fine adjustment through the double nut (27); Step 4: Tie up the steel skeleton of the concrete outside the pipe (5), assemble the steel formwork (32), and set the corbel (30) and self-adhesive rubber strip (31) at the bottom of the steel formwork (32); Step 5: hoist the outer hoop slurry collection device (33) so that the collection tank (41) is placed around the top of the steel template (32); Step 6: Insert the concrete conduit port (37) into the steel pipe rigid column (3) and start pouring self-compacting concrete in layers. The concrete (4) and air in the pipe flow into the annular groove (6) through the overflow slurry exhaust hole (17) until it is flush with the foundation pedestal (1). Continue pouring concrete in layers until the slurry (40) flows into the collection tank (41). Step 7: remove the outer hoop slurry collecting device (33), install the diversion rain cover (42), and maintain the concrete.

2. The construction method of square-cased circular steel tube reinforced concrete column according to claim 1 is characterized in that: In step 1: the diameter of the annular groove (6) is between the diameter of the steel pipe rigid column (3) and the outer size of the concrete outside the pipe (5); the inner pipe opening (9) of the U-shaped steel pipe (8) is located at a radius of 1 / 2 from the center of the annular groove (6), and the outer pipe opening (10) is located at the center of the overflow groove (7), and at the same time, the height of the inner pipe opening (9) is flush with the foundation pedestal (1), and the height of the outer pipe opening (10) is 3 to 5 cm lower than the foundation pedestal (1); embedded steel bars (11) are vertically installed around the annular groove (6), and the top of the embedded steel bars (11) is exposed to the foundation pedestal (1); column foot bolts (13) are provided at the designed position of the steel pipe rigid column positioning rib (12); After the initial setting of the concrete and before the final setting, a steel plate belt positioning ring (15) is installed on the surface of the annular groove (6). The steel plate belt positioning ring (15) is provided with a notch (14). The centers of the annular groove (6) and the steel plate belt positioning ring (15) are aligned, and the axis of the notch (14) is radially aligned with the column foot bolt (13). The outer diameter of the steel plate belt positioning ring (15) is smaller than that of the annular groove (6), and the inner diameter is consistent with the column foot plate (21) of the steel pipe rigid column (3). The shape and size of the notch (14) are consistent with the positioning rib plate (12) of the steel pipe rigid column (3), and are arranged in an annular symmetry.

3. The construction method of square-cased round steel tube reinforced concrete column according to claim 1 is characterized in that: In step 2: the steel pipe rigid column (3) includes a pipe wall (16), an overflow vent (17), a connecting rib (18), an inner partition (19), a column top plate (20), a column base plate (21), a positioning rib plate (12) and an ear plate (22), wherein the connecting rib (18) is symmetrically welded to the outside of the pipe wall (16), and the annular inner partition (19) is evenly welded to the inside of the pipe wall (16) in lanes; a column top plate (20) is provided at the upper end of the steel pipe rigid column (3), the column top plate (20) shrinks into the pipe and is symmetrically provided with four screw holes (23); the column base plate (21) expands outward from the pipe, and the column base plate (21) is symmetrically connected to the four positioning rib plates (12).

4. The construction method of square-sheathed circular steel tube reinforced concrete column according to claim 2 is characterized in that: In step three: the longitudinal level bubble (24) and the transverse level bubble (25) are long strips and are respectively installed at the longitudinal and transverse positions of the column base plate (21); the steel pipe rigid column (3) is vertically hoisted and dropped so that the through hole of the positioning rib plate (12) passes through the column base bolt (13) embedded in step one until it matches the gap of the steel plate belt positioning ring (15); then, the gasket (26) and the double nut (27) are installed in sequence at the column base bolt (13), and the double nut (27) is tightened to position the steel pipe rigid column.

5. The construction method of square-cased round steel tube reinforced concrete column according to claim 2 is characterized in that: In step 4: the steel reinforcement skeleton of the outer concrete (5) includes main reinforcement (28) and stirrups (29); wherein the main reinforcement (28) located outside the annular groove (6) is welded to the embedded reinforcement (11); and the steel formwork (32) is fastened and formed using tension bolts around the periphery.

6. The construction method of square-sheathed circular steel tube reinforced concrete column according to claim 1 is characterized in that: In step five: the outer hoop slurry collecting device (33) further includes a guide plate (34), a fixing bolt (35), a wall panel (43), a bolt groove (44), a slurry discharge hole (45) and a conduit (46); the slurry discharge hole (45) and the conduit (46) are arranged at the bottom of the collecting tank (41); the guide plate (34) and the steel template (32) are flush with each other; the wall panel (43) fits the outer side of the steel template (32), and the wall panel (43) is symmetrically provided with a plurality of bolt grooves (44); the outer hoop slurry collecting device (33) is slid up and down along the bolt groove (44) by the fixing bolt (35), and is finally supported on the horizontal back rib (36) of the steel template (32), and the fixing bolt (35) is tightened to completely fix the outer hoop slurry collecting device (33); glass glue is filled between the wall panel (43) and the steel template (32).

7. The construction method of square-sheathed circular steel tube reinforced concrete column according to claim 2, characterized in that: In step 6: before pouring, a layer of cement mortar with the same strength as the self-compacting concrete and a thickness of 100 to 200 mm is laid on the bottom; the lower end of the concrete conduit port (37) is higher than the structural surface by more than or equal to 4 meters, and when the concrete (4) in the pipe is poured, part of the air in the steel pipe rigid column (3) is discharged to the outside through the U-shaped steel pipe (8); When concrete continues to flow out of the outer pipe mouth (10) of the U-shaped steel pipe (8) into the overflow groove (7), it indicates that the height of the concrete (4) in the pipe is flush with the foundation pedestal (1). The concrete (4) in the pipe and the concrete (5) outside the pipe within the annular groove (6) are fully bonded with the inner partition (19), the connecting reinforcement (18), the column base plate (21) and the main reinforcement (28). The outer pipe mouth (10) of the U-shaped steel pipe (8) is tightened and sealed with a cap nut (38); and then the overflow groove (7) is filled and smoothed with expansion concrete (39). The strength of the expansion concrete (39) is higher than the concrete strength of the foundation pedestal (1).

8. The construction method of square-in-round steel tube reinforced concrete column according to claim 7 is characterized in that: In step 6: after the height of the concrete (4) in the tube is flush with the foundation pedestal (1), the overflow slurry groove (7) is first filled and smoothed, and then the high-throw concrete pouring is continued; when the pouring reaches the designed height of the steel tube rigid concrete column (2), the concrete (4) in the tube and the concrete (5) outside the tube both reach the maximum height; the self-compacting concrete drop height is reduced until the slurry (40) is collected in the collection groove (41) of the outer hoop slurry collection device (33) through the guide plate (34); When the floating slurry (40) is excessive, the floating slurry (40) is discharged and collected through the slurry discharge holes (45) and the conduit (46) at the bottom of the collecting tank (41).

9. The construction method of square-sheathed circular steel tube reinforced concrete column according to claim 1, characterized in that: In step seven, the bottom of the diversion rain cover (42) is flush and the top is umbrella-shaped, and the coverage area of the diversion rain cover (42) is larger than the steel tube reinforced concrete column (2); the diversion rain cover (42) is fixed to the top of the steel tube reinforced concrete column (2) through the screw hole (23) of the column top plate (20) of the steel tube reinforced concrete column (3); the diversion rain cover (42) also includes a hanging ring (47) and a nut (48); the nut (48) is consistent with the screw hole (23) of the column top plate (20).

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