High and large independent column building-free supporting frame construction method

Abstract

The invention provides a high and large independent column building-free support frame construction method, and relates to the technical field of independent column construction, and the method comprises the steps of corrugated pipe positioning pay-off and blanking, corrugated pipe fixing, bearing platform construction, bottom column construction, brick forming die construction, stand column reinforcement cage binding, steel structure and water and electricity embedded part installation, stand column steel die closing and hoisting, stand column concrete pouring and the like. The construction safety can be improved, the construction cost is reduced, and the construction speed is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of independent column construction, and specifically relates to a construction method for tall independent columns without building support frames. Background Art

[0002] With the continuous enhancement of the comprehensive strength of China's construction industry, the construction industry has developed towards green, professional, and diversified directions. The building structures of factory buildings have continuously moved closer to prefabricated combinations, resulting in large-span and large-space structural forms. In traditional concrete independent column construction, steel bars are usually reserved before the foundation concrete is poured, an operation scaffold is built, the steel bars are lengthened as the height increases, then wooden molds are assembled, and finally concrete is poured. If any process before and after the entire concrete pouring construction is handled improperly, problems such as pitted surfaces, formwork joints, offsets, and dimensional deviations of the column body will appear on the surface of the column, and the cycle of the entire construction process is also relatively long, with high investment in human and material costs.

[0003] Therefore, how to solve the construction problems of poor appearance quality and long construction period in tall independent column construction is a technical topic worthy of research. Summary of the Invention

[0004] In view of the above-mentioned prior art, the present invention proposes a construction method for tall independent columns without building support frames.

[0005] A construction method for tall independent columns without building support frames provided by the present invention includes the following steps: Step 1: Bellows positioning, layout, and cutting: A circle of bellows is set at the construction position of the independent column. After the bellows cutting is completed, the lower opening of the bellows is temporarily sealed. Step 2: Bellows fixation: A positioning mesh is set at intervals along the bottom circumference of the bellows. Step 3: Cap construction: Cap steel bars are tied at the bottom of the bellows, and the positioning mesh is connected and fixed to the cap steel bars. After the cap steel bars pass the acceptance, cap concrete is poured. Step 4: Bottom column construction: Bottom column steel bars are tied on the bellows and bottom column concrete is poured, and an annular widened platform is formed at the top of the bottom column. Step 5: Brick formwork construction: A 5 - 10 cm brick formwork is built on the top of the widened platform. Step 6: Column cage binding: A cross-shaped positioning bar is set at intervals along the circumference of the column cage. When binding the column cap cage, a concrete pouring port is reserved in the middle of the column cap cage, and at the same time, vibration rod holes are reserved at at least 4 corners. Step 7: Installation of steel structure and water and electricity embedded parts; Step 8: Hoisting and closing the column steel mold: Place a U-shaped steel mold flat on the ground, hoist the column steel cage into the U-shaped steel mold, and buckle the other U-shaped steel mold on the lower U-shaped steel mold and fix it; insert the column steel cage into the corrugated pipe, support the column steel mold on the widening platform, and introduce grouting material to consolidate the column steel cage and the corrugated pipe; Step 9: Pouring column concrete and removing column steel formwork: When pouring column concrete, first inject high-sand ratio concrete, and then pour normal grade concrete.

[0006] Preferably, in step 1, the lower opening of the corrugated tube is temporarily sealed with a finished product cover and transparent adhesive, and the sealing length does not exceed 10 cm.

[0007] Preferably, in step 2, the positioning mesh is made of steel bars with a diameter of not less than 16 cm.

[0008] Preferably, in step 4, when pouring the bottom column, the bottom column edge line is measured, the bottom column positioning ribs are corrected, the bottom column stirrups are installed, square and round buckles are installed on the bottom column formwork for reinforcement, the positioning ribs at the top of the bottom column extend out a certain distance and are closed with annular stirrups, and when pouring concrete at the top of the bottom column, each side is wider than the column edge by a certain distance to form a widened platform, and a pull ring is pre-embedded in the middle of each side of the widened platform.

[0009] Preferably, in step 6, a crisscross-shaped limiting steel bar is provided at the lower opening of the column cap steel bar cage, and extends out a certain distance from the side of the column steel bar cage.

[0010] Preferably, in step 8, steel cable wind ropes are arranged on four sides of the column steel formwork, and are tied to the hooks of the pedestal through a tensioner, a theodolite is used to check the verticality, and the tensioner is used to adjust each direction to ensure the verticality of the column steel formwork before tightening the tensioner.

[0011] Preferably, in step 9, four vibrators are inserted into the reserved holes for the vibrators at the corners of the column cap in advance, and dropped to the bottom of the column at one time. As the concrete is poured, the vibrators are lifted while being vibrated, using a vibrator no smaller than Type 50 and no less than 12 m in length.

[0012] Preferably, in step 9, 24 hours after the concrete is vibrated, the column steel formwork is removed, two U-shaped steel formworks are hung on hooks, all bolts are removed from top to bottom, the formwork removal bracket and the jack are installed, one side of the column steel formwork is pushed open, and it is hoisted to the ground, an L-shaped steel pipe clamp is installed at the bottom of the column steel formwork, one end of the jack is pressed against the steel pipe clamp, and the other end is pressed against the other U-shaped steel formwork, the jack is shaken to gradually open the U-shaped steel formwork, and after the U-shaped steel formwork on this side is separated from the concrete column, it is promptly hoisted to the ground, the inner surface is cleaned, and a maintenance-integrated release agent is applied.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. The present invention adopts an integrated design of a finished steel formwork. By prefabricating the reinforcement cage of the column on the ground, the construction is convenient, the quality is easy to control, and machines are used instead of manual labor, which improves work efficiency. At the same time, the erection of the support scaffold for tall independent columns is eliminated, the turnover rate of formwork materials is increased, the safety is improved, the construction cost is reduced, and the construction speed is accelerated.

[0014] 2. By using a demoulding and curing integrant in the tall steel formwork, the present invention realizes the exemption of moisture preservation and film covering curing for the concrete of the column body, saving a large amount of manpower and material resources and improving the construction quality.

[0015] 3. By optimizing and controlling the length and verticality of the embedded corrugated pipe, the corrugated pipe is installed at the corresponding height at one time, assisted by corresponding reinforcement measures, and the whole process measurement and on-site inspection before and during construction are strengthened, further improving the embedding accuracy, realizing the exemption of support erection for the upper vertical steel formwork, and improving the resource utilization rate of the formwork. Description of the Drawings

[0016] Figure 1 It is a schematic diagram of the embedding of the corrugated pipe in the bearing platform in the embodiment of the present invention.

[0017] Figure 2 It is a schematic side view of the leveling at the top of the bottom column in the embodiment of the present invention.

[0018] Figure 3 It is a schematic top view of the leveling at the top of the bottom column in the embodiment of the present invention.

[0019] Figure 4 It is a schematic diagram of the installation of the column steel formwork in the embodiment of the present invention.

[0020] Figure 5 It is a schematic structural diagram of the column reinforcement cage in the embodiment of the present invention.

[0021] Figure 6 It is a schematic diagram of the installation of the column cap reinforcement cage in the embodiment of the present invention.

[0022] Figure 7 It is a schematic diagram of the removal of the column steel formwork in the embodiment of the present invention.

[0023] Figure 8 It is a column bottom node diagram of the removal of the column steel formwork in the embodiment of the present invention.

[0024] Figure 9 It is a schematic structural diagram of the precast concrete pier in the embodiment of the present invention.

[0025] In the figure, 1 is a corrugated pipe; 2 is a positioning mesh; 3 is a bearing platform; 4 is a widened platform; 5 is a bottom column; 6 is a brick formwork; 7 is a foam rubber strip; 10 is a demoulding and curing integrated agent; 11 is a cross-shaped positioning bar; 12 is a jack; 13 is a steel pipe hoop; 14 is a U-shaped steel formwork; 15 is a column cap; 16 is a protective railing; 17 is a steel wire guy rope; 18 is a wire tightener; 19 is a conduit grouting hole; 20 is a vibrating rod reserved hole; 21 is a cross-shaped limiting steel bar; 22 is a column cap reinforcement cage; 23 is a main reinforcement bar of the column; 24 is a round steel hook; 25 is a precast concrete pier; 26 is a concrete column. Detailed implementation method

[0026] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

[0027] Example: As Figures 1-9 shown in a construction method for a high and large independent column without scaffolding support, including the following steps: Step 1: Positioning, setting out and cutting of the corrugated pipe: A circle of corrugated pipes 1 is arranged at the construction position of the independent column. The corrugated pipes 1 are metal corrugated pipes for prestressed concrete. When the diameter of the column reinforcement is less than or equal to 32 mm, the corrugated pipes 1 adopt 60-type metal corrugated pipes. When the diameter of the column reinforcement is greater than or equal to 36 mm, the corrugated pipes 1 adopt 80-type metal corrugated pipes; When positioning and setting out the corrugated pipes 1, verify information such as the elevation of the foundation bottom surface, the elevation of the bearing platform top surface, the number of corrugated pipe reinforcements, the spacing and the cross-sectional dimensions of the bottom column, etc., to determine the buried height of the corrugated pipes 1 and the pouring height of the bottom column concrete; Before cutting the corrugated pipes 1, clean and remove the grease; After the corrugated pipes 1 are cut, the lower openings of the corrugated pipes 1 are temporarily sealed with finished caps and transparent glue, and the sealing length does not exceed 10 cm to ensure that the pipe orifices are tightly sealed; Step 2: Fixing of the corrugated pipe: A positioning mesh 2 is arranged every 50 cm at the bottom circumference of the corrugated pipe. The positioning mesh 2 is made of steel bars with a diameter of not less than 16 cm; Step 3: Construction of the bearing platform: Tie the bearing platform reinforcement at the bottom of the corrugated pipe 1. The positioning mesh 2 is connected and fixed to the bearing platform reinforcement, and diagonal supports are arranged around to ensure the verticality of the positioning mesh 2. If the corrugated pipe 1 is displaced during the pouring process, the position of the corrugated pipe 1 needs to be adjusted in time; After the bearing platform reinforcement passes the acceptance, pour the bearing platform concrete; Before pouring the bearing platform concrete, check whether the corrugated pipe 1 is damaged or whether the upper and lower openings are tightly closed. Special persons are arranged to supervise before and during the vibration of the bearing platform concrete to ensure that it is not damaged and no garbage enters the corrugated pipe 1; Step 4: Construction of the bottom column: Tie the bottom column steel bars on the corrugated pipe 1 and pour the bottom column concrete; the height of the bottom column 5 is 2m. When pouring the bottom column concrete, first measure the bottom column side line, correct the positioning steel bars of the bottom column, install the stirrups of the bottom column, and install square-round fasteners on the bottom column formwork for reinforcement. The positioning steel bars at the top of the bottom column 5 extend 10cm and are closed with circumferential stirrups. When pouring the concrete at the column top of the bottom column 5, each side extends 10cm beyond the column side to form a widened platform 4 with a height of 10cm, which is convenient for the later erection of the column steel formwork; embed pull rings in the middle of each side of the widened platform 4. The pull rings are made of HPB300 Round steel bars with a diameter of 14 are inserted into the bottom column concrete and tied and fixed with the positioning steel bars of the bottom column, and the embedding depth is not less than 30cm; Step 5: Construction of the brick formwork: According to the height of the column steel form, build a brick formwork 6 with a height of 5-10cm on the top of the widened platform 4. To prevent the side of the brick formwork 6 from coming off under the action of the vibration force, use steel pipes to reinforce the four sides of the brick formwork 6 to ensure that there is no leakage or slurry running during the installation of the column steel formwork and the pouring of the column concrete; chisel the loose concrete on the top of the widened platform 4, clean it, cut off the upper opening of the corrugated pipe 1, and check whether there is water accumulation and sundries inside the corrugated pipe 1. If there is water accumulation, use a small vacuum pump to drain the water in the pipe, and use a steel bar tied with a dry cotton cloth to extend into the hole to wipe and adsorb the water adhering to the pipe wall and the bottom to ensure that the inside of the corrugated pipe 1 is dry and free of sundries; Step 6: Binding of the column steel cage: When binding the column steel cage, hang a sign in the column top area of each column steel cage to mark the axis position of the column and the direction information of the column top surface, which is convenient for the installation of steel structures and embedded pipelines for water and electricity; Set a cross-shaped positioning steel bar 11 every 2m around the column steel cage. The cross-shaped positioning steel bar 11 is made of steel bars with a diameter of 18mm. The length of each side of the cross-shaped positioning steel bar 11 is 5mm smaller than the size of the column steel form. The four corners are welded firmly. The cross-shaped positioning steel bar 11 can not only shape the column steel cage to prevent the column steel cage from falling apart or deforming during the hoisting process, but also assist in positioning the position of the main steel bars 23 of the column and control the effect of the column concrete protective layer; When binding the column cap steel cage 22, reserve a conduit grouting hole 19 with a size of 200*200mm in the middle, and at the same time reserve at least 4 vibration rod reserved holes 20 at the corners to facilitate the dropping of a 50-type vibration rod, and the length of the vibration hose is not less than 12m; to ensure that the column cap steel cage 22 does not fall during the hoisting process, weld a cross-shaped limit steel bar 21 with a diameter of 25mm at its lower opening and extend 100mm beyond the side of the column steel cage; Step 7: Installation of steel structure and embedded parts for water and electricity: When positioning the steel structure and embedded parts for water and electricity, ensure that the positions of the embedded parts installed are accurate, firmly fixed, control the embedded depth, reduce later chiseling, which may affect the appearance, and control the distance between the embedded parts and the concrete surface of the column at 5 mm; position the embedded parts by leading a line down from the top of the column cap; when there are lightning protection down conductors at the side columns and corner columns, tie and install the lightning protection down conductors in advance inside the columns, and leave a height of 50 cm during the hoisting process of the column steel formwork to facilitate timely welding of the down conductors; fix the steel structure and embedded parts of the water and electricity pipelines firmly by welding with fixed steel bars to prevent displacement during the vibration of pouring the column concrete. Step 8: Closing and hoisting of the column steel formwork: When closing the column steel formwork on the ground, first lay a U-shaped steel form 14 flat on the ground, and place square timbers under the U-shaped steel form 14 to ensure that the column cap is as horizontal as possible, with the overhanging length ≤ 1.5 m. Square timbers are strictly prohibited from being placed at the mid-span of the vertical square tubes of the steel form to avoid deforming the square tubes. Adjust the slope of the square timbers to minimize the distortion of the steel form as much as possible; before each use of the U-shaped steel form 14, clean the cement, rust, etc. on the surface. After cleaning, apply a demoulding and curing integrated agent 10. It is strictly prohibited to apply it at the joint position. The demoulding and curing integrated agent 10 can achieve the same effects of demoulding and curing, eliminating the daily maintenance of the columns; paste foam strips 7 at the joints and special-shaped corners to prevent the foam strips from falling during the closing process of the form, which can play a role in preventing leakage of slurry and improving the forming appearance quality of the column at the steel form joint; during the application of the demoulding and curing integrated agent 10, except for not applying it at the steel form joint, apply it evenly at other positions. This is convenient for protecting the appearance of the concrete column during demoulding, preventing the column concrete from sticking to the surface of the column steel form, and solving the problem of no later maintenance of the column. Lift the column steel reinforcement cage into the U-shaped steel form 14 by a truck crane, and check the direction of the column steel reinforcement cage and the embedded parts, etc. to ensure accurate positions. At the same time, check whether the cross-shaped limit steel bars 21 at the column cap are firmly welded; buckle another U-shaped steel form 14 on the lower U-shaped steel form 14 and fix it. With the assistance of a crowbar, align the bolt holes of the column steel form, slowly position it, insert and initially tighten the first bolt at both ends, adjust the levelness of the lower U-shaped steel form 14 while inserting all bolts; finally tighten symmetrically and simultaneously from both sides at one end, and the torque should reach more than 280 N·m; finally, check whether the column steel form is deformed, especially the flatness at the joint, to prevent leakage of slurry; insert a tool-type guardrail 16 at the upper end of the column cap 15 and weld it into the steel hole of the column steel form and fix it firmly. The installation height of the guardrail 16 is 1.5 m; when hoisting the column steel form, use a lifting beam at the top to separate the steel wire rope from the guardrail 16. The main hook and the auxiliary hook rise simultaneously to lift the column steel form a certain height above the ground. Lift the main hook and relax the auxiliary hook to lift the column steel form to a vertical state. To avoid collision between the steel wire and the guardrail, etc., the main hook is additionally hung with a lifting beam and connected to the upper end of the column steel form. After the bellows 1 is cleared of holes, a special grouting material mixer truck is used to mix the grouting material. First, water is added, and then the grouting material is added. The water-cement ratio is strictly controlled according to the manufacturer's mix ratio requirements. The grouting material uses a high-strength non-shrinking special grouting material with a strength not lower than C60; the grouting material is mixed in small amounts and multiple times, and used immediately after mixing to prevent precipitation; the column steel reinforcement cage is inserted into the bellows 1, the column steel formwork is supported on the widened platform 4, and the mixed grouting material is introduced to consolidate the column steel reinforcement cage and the bellows 1, ensuring that the grouting material fully covers the pipe orifice. The earliest grouting start time to the time when the column's steel bars are inserted is not more than 30 minutes; the grouting material needs to be directly poured into the bellows 1 to avoid the grouting material remaining in the column cross-section area. At the same time, the inserted steel bars can be lifted up and down to check the grouting situation; The verticality adjustment of the column steel formwork is carried out under the condition that the crane loosens the steel wire rope but does not unhook. The steel wire guy ropes 17 on the four sides of the column steel formwork are tied to the round steel hooks 24 of the bearing platform 3 through 2t wire tighteners 18. The theodolite is used to check the verticality, and each direction is adjusted through the wire tightener 18. After ensuring the verticality of the column steel formwork, the wire tightener 18 is tightened. The steel wire guy ropes 17 of the middle column are fixed to the hooks of the bearing platform 3, and the steel wire guy ropes 17 of the side columns and corner columns are fixed at the temporary concrete road surface; when there is no fixed point for the pull point of the column steel formwork, a precast concrete pier 25 with a size of 1m * 1m * 0.8m is buried in the soil in advance and the surrounding is compacted. Two M16 * 140 expansion bolts are used on the precast concrete pier 25 to fix the embedded round steel hook 24 as the pull point of the steel wire guy rope 17. The steel wire guy rope 17 is wrapped with a conspicuous colored strip cloth to prevent the crane operation from hitting the steel wire guy rope 17 and affecting the verticality of the column steel formwork; Step 9: Pouring the column concrete and removing the column steel formwork: Since the pouring height of the column concrete is relatively high, before the concrete pouring, it is required that the commercial concrete company design a reasonable mix ratio according to the column cross-section, steel bar spacing, and pouring height, and control the concrete slump at 180mm to ensure the quality of the concrete pouring and forming, without segregation or bleeding; when pouring the column concrete, first inject high-sand-rate concrete (the concrete is one grade higher) with a height of 800mm, and then pour the normal-grade concrete. Pouring the high-sand-rate concrete at the bottom of the column can play a buffering role to reduce the segregation generated when the upper concrete falls; At the corner of the column cap, four vibrators are inserted into the reserved holes 20 of the vibrators in advance, and dropped to the bottom of the column at one time. As the concrete is poured, the vibrators are lifted while vibrating. A vibrator of no less than 50 type and a length of no less than 12m are used; when vibrating the column cap, no less than 4 operators are arranged, each of whom controls a vibrator. The vibration is reasonably controlled during the vibration and cannot be over-vibrated. To avoid excessive concrete pouring speed, the pouring speed is controlled within 25-30min; to avoid the concentrated sinking of stones and the floating of cement slurry during the vibration of the column cap concrete, which affects the strength of the column top concrete, 1-2 buckets (capacity 5L) of stones are spread at the end of the column cap pouring, and the laitance is scraped off in time as the vibrating is performed, and if the laitance is thick, the laitance is removed and the concrete is poured again to ensure the strength of the column cap concrete; the verticality of the column is calibrated for the first time before the concrete is poured, and it is checked again immediately after the concrete pouring is completed. If tilting occurs, the tensioner 18 is used in time to adjust the column; 24h after the concrete is vibrated (extended to 36h when the temperature is below 10℃), remove the column steel mold, loosen the wire rope 17, hang the two U-shaped steel molds 14 on the hook, remove all bolts from top to bottom, install the mold removal bracket and jack 12, push open one side of the column steel mold, and use a car crane to lift the opened column steel mold to the ground, install an L-shaped steel pipe clamp 13 at the bottom of the column steel mold, use one end of the jack to push the steel pipe clamp 13, and the other end to push on the other U-shaped steel mold 14, shake the jack to gradually push open the U-shaped steel mold 14, and after the U-shaped steel mold 14 on this side is separated from the concrete column 26, it is lifted to the ground in time with a car crane, the inner surface is cleaned and the curing integrated mold release agent is applied; a finished 1.5*1.5*1m plastic bag is used to cover the top of the column cap 15, and water is sprinkled to keep it moist for 7 days.

[0028] In this embodiment, the buried height of the corrugated pipe 1 includes both the straight anchor length buried in the pedestal 3 and the free height of the bottom column 5, realizing a construction method in which when there is a 2m high bottom column, the column steel cage is directly inserted into the corrugated pipe 1 and consolidated into a whole through high-strength grouting material.

[0029] In this embodiment, a corrugated pipe 1 of sufficient length for direct anchoring is embedded in the foundation as a steel bar hole. Two U-shaped steel molds are spliced ​​on the upper part and assembled into one with the column steel cage. The mold is inserted into the hole of the direct anchor corrugated pipe by hoisting, and then the direct anchor hole is solidified by high-strength grouting material. In addition, the column steel mold is fixed by the integral casting mode of steel wire cable wind rope tie around, which makes full use of the self-anchoring stability of the steel bars at the bottom of the column steel cage. With the tie and fixation of the upper steel wire cable wind rope, the independent column steel mold is constructed without support. At the same time, the construction method is simple to operate and efficient, which greatly reduces the investment of construction costs and speeds up the turnover rate of template materials. After completion, the independent column molding can achieve the effect of clear concrete, which improves the overall quality of the building.

[0030] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent solutions made by using the content of the specification of the present invention and directly or indirectly applied in other related technical fields shall be similarly within the patent protection scope of the present invention.

Claims

1. A method for constructing a tall independent column without a support frame, characterized in that: The steps include: Step 1: Positioning, laying out and cutting of the corrugated pipe: A circle of corrugated pipe is set at the construction position of the independent column. After the cutting of the corrugated pipe is completed, the lower end of the corrugated pipe is temporarily sealed; Step 2: Fixing the bellows: A positioning mesh is arranged at intervals on the bottom circumference of the bellows; Step 3: Cap construction: Tie the cap reinforcement at the bottom of the corrugated pipe, connect and fix the positioning mesh with the cap reinforcement, and pour the cap concrete after the cap reinforcement is accepted; Step 4: Bottom column construction: tie the bottom column steel bars on the corrugated pipe and pour the bottom column concrete, and form a circular widening platform on the top of the bottom column; Step 5: Brick membrane construction: build a 5-10 cm brick membrane on the top of the widened platform; Step 6: Binding of column reinforcement cage: set a well-shaped positioning bar at intervals around the periphery of the column reinforcement cage. When binding the column cap reinforcement cage, reserve a concrete pouring opening in the middle of the column cap reinforcement cage, and reserve at least 4 corner holes for the vibration rod; Step 7: Installation of steel structure and water and electricity embedded parts; Step 8: Hoisting and closing the column steel mold: Place a U-shaped steel mold flat on the ground, hoist the column steel cage into the U-shaped steel mold, and buckle the other U-shaped steel mold on the lower U-shaped steel mold and fix it; insert the column steel cage into the corrugated pipe, support the column steel mold on the widening platform, and introduce grouting material to consolidate the column steel cage and the corrugated pipe; Step 9: Pouring column concrete and removing column steel formwork: When pouring column concrete, first inject high-sand ratio concrete, and then pour normal grade concrete.

2. The method for constructing a tall independent column without supporting frame according to claim 1, characterized in that: In step 1, the lower end of the corrugated tube is temporarily sealed with a finished product cover and transparent adhesive, and the sealing length does not exceed 10 cm.

3. The method for constructing a tall independent column without supporting frame as claimed in claim 1 or 2, characterized in that: In step 2, the positioning mesh is made of steel bars with a diameter of not less than 16 cm.

4. The method for constructing a tall independent column without supporting frame as claimed in claim 1 or 2, characterized in that: In step 4, when pouring the bottom column, measure the bottom column edge line, correct the bottom column positioning reinforcement, install the bottom column stirrups, install square and round buckles on the bottom column template for reinforcement, the positioning reinforcement at the top of the bottom column extends a certain distance and is closed with annular stirrups. When pouring concrete on the top of the bottom column, each side is wider than the column edge by a certain distance to form a widened platform, and a pull ring is pre-embedded in the middle of each side of the widened platform.

5. The method for constructing a tall independent column without supporting frame as claimed in claim 1 or 2, characterized in that: In step 6, a criss-cross-shaped limiting steel bar is set at the lower end of the column cap steel cage, and extends a certain distance from the side of the column steel cage.

6. The method for constructing a tall independent column without supporting frame as claimed in claim 1 or 2, characterized in that: In step 8, steel cable wind ropes are set on the four sides of the column steel formwork and tied to the hooks of the pedestal through a tensioner. The verticality is checked with a theodolite, and the tensioner is adjusted in each direction to ensure the verticality of the column steel formwork and then the tensioner is tightened.

7. The method for constructing a tall independent column without supporting frame as claimed in claim 1 or 2, characterized in that: In step 9, four vibrators are inserted into the reserved holes for the vibrators at the corners of the column cap in advance, and dropped to the bottom of the column at one time. As the concrete is poured, the vibrators are lifted while being vibrated. Use a vibrator no smaller than Type 50 and no less than 12m in length.

8. The method for constructing a tall independent column without supporting frame as claimed in claim 1 or 2, characterized in that: In step 9, 24 hours after the concrete is vibrated, the column steel formwork is removed, the two U-shaped steel formworks are hung on hooks, all bolts are removed from top to bottom, the formwork removal bracket and jack are installed, one side of the column steel formwork is pushed open, and it is hoisted to the ground, an L-shaped steel pipe clamp is installed at the bottom of the column steel formwork, one end of the jack is pressed against the steel pipe clamp, and the other end is pressed against the other U-shaped steel formwork, and the jack is shaken to gradually open the U-shaped steel formwork. After the U-shaped steel formwork on this side is separated from the concrete column, it is promptly hoisted to the ground, the inner surface is cleaned, and the maintenance-integrated release agent is applied.

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