A quick hoisting sling and hoisting process for the steel column support of a cast-in-place beam

Abstract

A quick hoisting sling and hoisting process for the steel column support of a cast-in-place beam. The sling clamps the steel column, and the steel wire rope bypasses the other half of the steel column. The steel wire rope and the self-made sling are fixed together through a U-shaped snap ring. When hoisting the steel column, due to the gravity of the steel column, the steel wire rope is automatically tightened, forming a trend that the heavier the hoisted heavy object is, the higher the locking degree of the sling to the steel column is, and the steel column is successfully hoisted. When the steel column is hoisted in place and firmly fixed to the foundation to ensure that it will not tilt or overturn after the hook is removed, the operator drags the cable tied to the sling, and the hoisting steel wire rope of the steel column and the sling can slide down along the steel column to the ground together. Then, the U-shaped snap ring is loosened to carry out the hoisting work of the next steel column. It solves the problem that the hoisting of the steel column is prone to unhooking.

Description

Technical Field

[0001] The invention belongs to the technical field of construction hoisting, and in particular relates to a quick hoisting sling for cast-in-place beam steel column supports and a hoisting process. Background Art

[0002] In today's rapidly developing economy and society, a series of large-span, complex, and special-shaped bridges, such as cable-stayed bridges and rotating bridges, are constantly being developed. However, these bridges are often restricted by existing railways and highways. Without disrupting or threatening existing railway and highway operations, rotating bridges have become the preferred construction option, and cable-stayed rotating bridges have become a new trend in the development of large-span rotating structures. The cast-in-place method for rotating beam scaffolding, with its fast construction speed, high safety factor, and low cost, has become the primary method for cast-in-place rotating beam construction. Currently, the steel columns of the cast-beam scaffolding system present construction safety risks, difficulty in unhooking after installation, and the need for multiple mechanical installations. Summary of the Invention

[0003] In order to overcome the deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide a cast-in-place beam steel column support rapid lifting sling and lifting process, combined with the construction characteristics under soft stratum conditions, from the aspects of shortening the construction period, reducing construction costs, reducing construction safety risks, and improving environmental protection, the design and construction of the cast-in-place beam scaffolding system steel column are comprehensively considered, a conventional automobile crane is used to realize multi-directional construction and use of one machine, a homemade simple sling is used to realize the lifting and installation of the steel column, the problem of difficulty in unhooking the steel column after installation is solved, and the temporary construction investment for replacement and filling treatment of a one-time construction site during multi-machine construction is avoided, which not only saves the cost of using machinery and materials, but also avoids the pollution to the environment caused by site treatment, and further improves the lifting construction efficiency, has a high safety factor, simple operation, reduces construction costs, shortens the construction period, and especially solves the problem of easy unhooking of the steel column during lifting and hoisting.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A cast-in-place beam steel column support rapid lifting sling and lifting process, characterized by comprising the following steps:

[0006] Step 1: Construction preparation:

[0007] Site preparation, steel column foundation construction, steel column material delivery, lifting equipment delivery, and material delivery acceptance;

[0008] Step 2: Measure foundation elevation;

[0009] After the concrete strip foundation is completed and before the steel columns are installed, the actual elevation of the strip foundation steel column installation position needs to be re-measured, and the elevation error should be less than 5mm;

[0010] Step 3, Treatment of the foundation top surface;

[0011] Level the foundation top surface, clean the soil on the foundation top surface, and straighten the anchor bars;

[0012] Step 4, Measurement of the length of the steel column;

[0013] There are different degrees of deviations in the use of steel columns. Moreover, with the undulation of the terrain, the elevation of the strip foundation top surface at different positions is not the same. However, the top surface of the steel column must be adjusted to a horizontal plane to ensure the smooth subsequent construction of the Bailey beam, the disc buckle scaffold, etc. Therefore, when installing the steel column, it is necessary to adjust the length of the steel column according to the foundation elevation. After the steel column is delivered to the site, according to the foundation elevation and the control elevation at the top of the steel column, the actual length of the steel column is adjusted through the adjustment section of the steel column;

[0014] Step 5, Fabrication of the lifting appliance;

[0015] According to the outer diameter size of the steel column, the weight of the connecting flange plate of the steel column, etc., and considering a safety factor of 1.2, combined with the shape of the lifting appliance, it is calculated that the lifting appliance is fabricated on-site with a steel plate of t = 20 mm. The structure of the lifting appliance is semi-circular, with round holes at both ends and a connecting ear plate in the middle;

[0016] Step 6, Erection of the hoisting machinery;

[0017] For the installation of the steel column, a 25t truck crane is selected for hoisting operations; the site is processed in advance. When the truck crane is parked, after all outriggers are erected, it should be ensured that the truck crane is on a horizontal plane, and sleepers must be laid at the bottom of all outriggers;

[0018] Step 7, Installation of the sling and the lifting appliance;

[0019] During hoisting, the hoisting wire rope is wound around the front end of the steel column to be installed, and the hoisting wire rope is connected to the lifting appliance through a U-shaped snap ring and hung on the hook of the truck crane. The wire rope wound around the front end of the steel column is in close contact with the flange plate of the steel column. After the U-shaped snap ring is installed, the U-shaped ring can move freely during hoisting;

[0020] Step 9, Hoisting of the steel column;

[0021] After meeting the hoisting conditions, hoist the steel column; when the crane lifts, the wire rope automatically tightens under the tension of the self-weight of the steel pipe, tightly hugs and clamps the steel column together with the lifting appliance, and then is lifted;

[0022] Step 10, Fixing of the steel column;

[0023] After the steel column is moved to the installation position, the crane is commanded to adjust the installation position of the steel column and ensure the verticality of the steel column. The installation workers install a magnetic level on the side wall of the steel column to determine the verticality of the steel column. The steel column is fine-tuned with a crowbar and a wedge-shaped steel plate to ensure the verticality of the steel column. After the adjustment is in place and meets the requirements, the anchor steel bars embedded in the foundation of the steel column are bent until they are tightly attached to the steel column and then welded together. After the anchor steel bars are connected, a template is installed around the bottom of the steel column base, and then the support is grouted and sealed with a support grouting material with an elevation of not less than C50 to ensure that there is no gap between the steel column and the base.

[0024] Step 11, unloading the sling and spreader;

[0025] After the steel column is firmly fixed, loosen the hook of the car crane, manually pull the cable tied to the spreader, slide the wire rope tied to the steel column down along the spreader hole of the steel column and loosen it, and the spreader falls freely to the ground; completing one lifting.

[0026] The manual pulling of the cable tied to the sling can reduce the angle between the cable and the steel column as much as possible when the cable tied to the sling is pulled down, so that the steel column sling can be more easily separated from the steel column.

[0027] If the actual elevation is remeasured and exceeds the elevation error, measures need to be taken in advance to process the concrete surface of the steel column foundation. If the concrete surface elevation is uneven or exceeds the allowable error, the concrete surface needs to be chiseled off, or steel columns that can meet the actual construction needs are made to cope with the actual support column foundation elevation. If the top elevation of the strip foundation is low, self-compacting concrete pouring, steel plate padding, or steel columns of equivalent length can be made according to the actual elevation.

[0028] The diameter of the lifting wire rope is 20mm. If it is too thick or too thin, it will be difficult to lift. If it is too thick, the wire rope will be easily stuck by the clamp and difficult to remove; if it is too thin, the safety factor is not high and it is easy to break.

[0029] The width of the site treatment should be at least one meter wider than the width of the truck crane legs. If it is backfill soil, the original site should be excavated at least 30 cm and then leveled and compacted. After the treatment is completed, a 30 cm thick layer of crushed stone should be laid, or a 20 cm thick C20 concrete should be hardened to improve the bearing capacity of the site foundation.

[0030] The beneficial effects of the present invention are:

[0031] The present invention is adapted to the hoisting of similar steel columns. Compared with the conventional construction method of steel columns, it realizes the convenience, speed and safety in the hoisting and unhooking processes of steel columns. The input of personnel and machinery is greatly reduced. Unnecessary site leveling treatment is avoided, the risk of high-altitude construction operations is avoided, and intangible input is reduced. By using the invention in construction, construction costs are saved, the construction period is shortened, the operation procedures are optimized, construction safety is ensured, and good economic and social benefits are achieved.

[0032] Economic benefits:

[0033] Site treatment cost

[0034] The site for installing steel columns in this project is 290 m long and 30 m wide. If a conventional aerial work platform is used for high-altitude operations of steel columns, the total area of the site that needs to be leveled is 8,700 m². When using the current hoisting tools for steel column hoisting and installation, only the site where the crane needs to be parked needs to be leveled, avoiding large-scale site leveling. When using this construction method for steel column hoisting, the crane is parked at a total of 6 locations. That is to say, only these six locations where the crane needs to be parked and the access roads to the parking locations need to be treated, and the rest of the site remains unchanged.

[0035] The width of the temporary access road for the hoisting machinery is 3.5 m, the width of the site for machinery parking is 7 m, and the length is 9 m. The site is treated by laying a 40-cm-thick crushed stone cushion. When using the conventional aerial work platform for construction operations, 3,480 m³ of crushed stone is required for site leveling, while only 243.6 m³ of crushed stone is required for the site treatment using this construction method. Calculated according to the current price of crushed stone material at 150 yuan / m³ and the construction machinery costs of loaders and rollers (4 yuan / m²), the cost can be saved approximately (3,480 - 243.6) * 150 yuan / m³ + (8,700 - 609) * 8 yuan / m² = 550,000 yuan.

[0036] Rental of aerial work platforms for high-altitude operations:

[0037] A total of 238 steel columns need to be installed in this project. When using an aerial work platform for steel column installation in the early stage, an average of 7 steel columns are installed per day, and the rental cost of the aerial work platform is approximately 800 yuan / day. If a conventional aerial work platform is used for operations, the rental cost of the aerial work platform consumed is 238 / 7 * 800 = 27,200 yuan.

[0038] Input of construction workers:

[0039] If a working platform is used for working at height, when installing the steel columns, 2 additional construction workers are required. Calculated according to the current labor cost of skilled workers at 320 yuan per day, the additional labor cost for construction workers is 238 / 7*320*2 = 21,800 yuan.

[0040] Analysis of project duration cost

[0041] When using the steel column lifting tool for hoisting the steel columns, the time of using the working platform is saved. On average, 10 steel columns can be installed per day, and the installation speed is increased. Compared with using the working platform for operation, the construction period can be saved by 238 / 7 - 238 / 10 = 10 days. During the shortened construction period, the rental fee of the existing leased machinery, the labor cost of the existing construction workers, and other intangible expenses are saved. Calculated according to the average cost of the current project at 3,000 yuan per day, the project duration cost can be saved by 10 days * 3,000 yuan = 30,000 yuan.

[0042] Based on the above analysis, using this kind of steel column lifting tool for steel column hoisting construction reduces the construction operation cost, and the economic benefit saved is: 55 + 27,200 + 21,800 + 30,000 = 629,000 yuan.

[0043] Social benefits

[0044] 1. The present invention truly solves the problem of working at height in steel column hoisting, avoids the risks existing in the working at height of construction workers during the steel column hoisting operation, reduces the input of personnel and machinery, and reduces the leveling cost of the construction site for one-time use.

[0045] 2. If a working platform is used for construction operation, the construction site needs to be paved and leveled before construction, and after the construction is completed, the materials on the temporary construction site need to be cleared to restore the original site, and the construction waste generated is also a kind of pollution to the environment.

[0046] 3. The additional construction machinery invested and the waste generated will all have an impact on the environment.

[0047] 4. Using the steel column lifting tool greatly saves the construction period and construction cost, and has won the unanimous praise of the owner, supervisor and brother units, and improves the competitiveness of the company.

[0048] 5. The lifting tool adopted by the present invention accumulates experience and provides reference for the construction of subsequent similar projects. Description of the drawings

[0049] Figure 1 It is the process flow chart of the present invention.

[0050] Figure 2 It is the structure schematic diagram of the lifting tool of the present invention.

[0051] Figure 3 It is a scene implementation diagram of the present invention. DETAILED DESCRIPTION

[0052] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0053] like Figure 1 、 3 As shown, a cast-in-place beam steel column support rapid lifting sling and lifting process includes the following steps:

[0054] Step 1: Construction preparation:

[0055] (1) Site preparation: three connections and one leveling, repair the construction access road, and ensure that the construction access road is solid, has smooth drainage, and is free of potholes.

[0056] (2) Steel column foundation construction, including bored cast-in-place piles and strip foundation construction.

[0057] (3) Delivery, mixing and modification of steel column materials.

[0058] (4) The lifting equipment and materials must be inspected upon arrival and can only be used after they are qualified.

[0059] Step 2: Measure foundation elevation;

[0060] The foundation design of the cast-in-place beam support of the rotating bridge is bored cast-in-place piles and concrete strip foundations. After the strip foundation construction is completed, before the steel columns are installed, the actual elevation of the strip foundation steel column installation position needs to be re-measured. The elevation error should be within 5mm. If the elevation error is exceeded, measures need to be taken in advance to treat the concrete surface of the steel column foundation. If the concrete surface elevation is uneven or the elevation exceeds the allowable error, the concrete surface needs to be chiseled off, or steel columns that can meet the actual construction needs need to be made to cope with the actual support column foundation elevation. If the strip foundation top elevation is low, self-compacting concrete pouring, steel plate padding, or steel columns of equivalent length can be made according to the actual elevation;

[0061] Step 3: Process the top surface of the foundation;

[0062] During the construction of the steel column foundation, steel column anchor steel bars and foundation top elevation control points are pre-buried. However, due to construction reasons, there may be uneven areas on the top surface of the foundation or the anchor steel bars are not vertical. Therefore, before the steel column is hoisted, the top surface of the foundation must be leveled, the soil on the top surface of the foundation must be cleaned, and the anchor steel bars must be straightened to ensure that the steel column can be hoisted smoothly.

[0063] Step 4: Measure the length of the steel column;

[0064] A large number of steel columns are used and supplied by multiple manufacturers. There are varying degrees of deviations in both the specific dimensions and the connecting holes of the flange plates. When designing the steel column foundation, it is adjusted according to local conditions, and the foundation elevation is also designed along with the undulations of the terrain. Therefore, the top elevations of the strip foundations at different positions are not the same. However, the top surfaces of the steel columns must be adjusted to a horizontal plane to ensure the subsequent smooth construction of the Bailey beams, disk buckle scaffolds, etc. Therefore, when installing the steel columns, the lengths of the steel columns need to be adjusted according to the foundation elevation.

[0065] After the steel columns enter the site, according to the foundation elevation and the control elevation at the top of the steel columns, the actual length of the steel columns is adjusted through the adjustment joints of the steel columns.

[0066] Step 5: Hoisting tool fabrication;

[0067] According to the outer diameter size of the steel columns, following the principles of safe, convenient hoisting and unloading, fabricate the hoisting tools for the steel columns. Since the steel columns used in this project are all of the same diameter and the requirements for the hoisting tools are simple, as long as they can achieve the purpose of safe hoisting. The specification size of the steel columns is 609x16, the maximum length is 8m. Together with the weight of the connecting flange plates of the steel columns, the maximum weight of a single steel column for hoisting is 2t. Considering a safety factor of 1.2 and calculating based on the shape of the hoisting tool, it is found that the hoisting tool is fabricated on-site using a steel plate with t = 20mm. The structure of the hoisting tool is semi-circular, with round holes at both ends and a connecting ear plate in the middle, as Figure 2 shown.

[0068] Step 6: Erection of the hoisting machinery;

[0069] For the installation of the steel columns, a 25t truck crane is selected for hoisting operations. It is required to select mechanical equipment with good performance and passing the annual inspection. The hoisting driver should have an operation license, have received professional training, and have no records of illegal crimes, etc.

[0070] The site where the truck crane is placed should be flat and solid, and should not be placed in a low-lying area. The drainage around should be unobstructed to ensure no water accumulation. The site for placing the truck crane should be treated in advance. The width of the site treatment should be at least one meter wider than the width of the truck crane's outriggers. If it is backfilled soil, the original site should be dug and turned over by at least 30cm and then leveled and compacted. After the treatment, lay a layer of 30cm thick crushed stones, or harden 20cm thick C20 concrete to improve the bearing capacity of the site's foundation.

[0071] When the truck crane is parked, all outriggers should be fully extended, and it is prohibited to only extend some outriggers. After all outriggers are erected, it should be ensured that the truck crane is on a horizontal plane to avoid the truck crane being in an inclined state. At the bottom of all outriggers, sleepers must be laid to spread the pressure exerted by the outriggers on the foundation and reduce the bearing stress of the outriggers on the foundation. When erecting the outriggers, it is prohibited to support on pipelines, cables or other shallowly buried underground structures.

[0072] Step 7: Installation of slings and lifting appliances

[0073] Before the installation of steel columns, they are generally placed flat on the ground. During hoisting, the hoisting wire rope is wound around the front end of the steel column to be installed and connected to the lifting appliance through a U-shaped snap ring, and then hung on the hook of the truck crane. The diameter of the hoisting wire rope is 20 mm. Being too thick or too thin is not conducive to hoisting. Being too thick will cause the wire rope to be easily stuck by the snap ring and difficult to unload; being too thin, the safety factor is not high and it is easy to break. The wire rope wound around the front end of the steel column must be in close contact with the flange of the steel column to prevent the wire rope from falling off the flange of the steel column during hoisting. The U-shaped snap ring must be intact without quality defects such as cracks; when installing the snap ring, the bolts must be tightened, and the U-shaped ring should be able to move freely during hoisting.

[0074] Step 9: Hoisting of steel columns

[0075] After the lifting appliances and wire ropes are installed firmly and meet the hoisting conditions, hoisting is carried out. The wire rope automatically tightens under the tension of the self-weight of the steel pipe, hugs and clamps the steel column together with the lifting appliance, and then is lifted. During the hoisting process of the steel column, it should be safe and stable, avoiding collisions between the steel column and external objects. After the steel column is vertically hoisted and completely lifted off the ground, then rotate the crane to horizontally move the steel column, and the movement should be slow. During the hoisting process of the steel column, construction workers should stay away from the steel column and are prohibited from standing under the hoisting boom. The cable tied to the lifting appliance is prohibited from being pulled forcefully to prevent the lifting appliance and the wire rope from detaching from the steel column and causing danger.

[0076] Step 10: Fixing of steel columns

[0077] After the steel column is moved to the position to be installed, slowly lower the wire rope of the crane. Construction workers support the steel column and command the crane to adjust the installation position of the steel column and ensure the verticality of the steel column. After the installation position of the steel column is in place and the verticality is visually inspected to meet the requirements, stop the operation of the crane. The installation worker installs a magnetic level on the side wall of the steel column to determine the verticality of the steel column, and uses a crowbar and a wedge-shaped steel plate to finely adjust the steel column to ensure the verticality of the steel column.

[0078] After the adjustment is in place and meets the requirements, bend the embedded anchor bars on the steel column foundation to be in close contact with the steel column and then carry out welding connection to ensure that there is no dislocation between the steel column and the foundation; after the connection of the anchor bars is completed, install formwork around the bottom of the steel column base, and then use grouting material for supports with a strength grade not lower than C50 to grout and seal the supports to ensure that there is no gap between the steel column and the base.

[0079] Step 11: Removal of slings and lifting appliances

[0080] After the steel column is firmly fixed, loosen the hook of the truck crane, and manually pull the cable tied to the lifting appliance. Then, the steel wire rope tied to the steel column can slide down along the hole of the steel column lifting appliance and become loose, and the lifting appliance can freely fall to the ground. The construction workers can then loosen the lifting appliance, the hoisting wire rope, etc. on the steel column on the ground, thus easily removing the steel column lifting appliance.

[0081] When pulling down the cable tied to the lifting appliance, try to minimize the angle between the cable and the steel column, so that it is easier to ensure that the steel column lifting appliance is separated from the steel column. Pay attention to safety during the process of removing the wire rope. Wear a safety helmet and protective gloves to prevent injuries caused by hard materials such as wire ropes and lifting appliances hitting the head, and avoid the burrs on the wire rope piercing the fingers during the operation process.

[0082] The principle of the present invention is;

[0083] The steel column hoisting system mainly includes a 25t truck crane, a steel wire rope, a U-shaped snap ring, a self-made lifting appliance, a cable, etc. The self-made lifting appliance used is clamped on the steel column, and the steel wire rope bypasses the other half of the steel column. The steel wire rope and the lifting appliance are fixed together through a U-shaped snap ring. When hoisting the steel column with the steel wire rope and the self-made lifting appliance, due to the gravity of the steel column, the steel wire rope is automatically tightened, forming a trend that the heavier the weight of the hoisted heavy object, the higher the locking degree of the lifting appliance to the steel column, and the steel column is successfully hoisted. The size of this lifting appliance is particularly important during the manufacturing process. The size of the lifting appliance will affect the verticality of hoisting the steel column, the locking degree of hoisting, the ease of unhooking, etc. As shown in the figure, when manufacturing this lifting appliance, the inner diameter size should be slightly larger than the outer diameter of the steel column by 2 - 3 cm, and at the same time, it should be slightly open outward to facilitate unhooking; the two steel wire rope holes on both sides of the lifting appliance should be located on the diameter of the inner diameter of the lifting appliance, so as to ensure that the steel pipe column can be in a vertical state during hoisting. When the steel column is hoisted in place and firmly fixed to the foundation, ensuring that it will not tilt or overturn after unhooking, the operator drags the cable tied to the lifting appliance, and then the hoisting wire rope of the steel column and the lifting appliance can slide down along the steel column to the ground together. Then loosen the U-shaped snap ring to carry out the hoisting work of the next steel column. Embodiment

[0084] The overpass bridge across the North Tongpu Railway on the project of the east extension of Xinyang Avenue and its supporting ancillary facilities in Yangqu County, Taiyuan City:

[0085] Project overview:

[0086] As an urban arterial road in the core area of Yangqu County, the east extension of Xinyang Avenue starts from Shouyi Road in the west and ends at Shuangyang Road in the east. The road runs from east to west, and an overpass scheme is adopted at the Yangqu Railway Station node.

[0087] The total length of the overpass bridge is 540m, with the design mileage range from K1+345.726 to K1+885.726. The main bridge adopts a single-tower cable-stayed bridge with a span of (2x150)m and a width of 26.18m. The approach bridges adopt continuous box girders with a width of 19 - 26.18m. The span layout is: (2×43)m continuous box girder + (2×39)m continuous box girder + (2×150)m single-tower cable-stayed bridge + (2×35)m continuous box girder. The bridge deck has a 1.5% cross slope in both directions. The cross slope at the bottom of the cast-in-place beam of the approach bridge is the same as that of the bridge deck, and the cross slope at the bottom of the cast-in-place beam of the main bridge is 0.

[0088] The main beam is divided into six segments according to the construction method, which are the 0# segment at the main tower, the general cast-in-place segments 1# - 4#, the cast-in-place segment 6# at the side pier, and the closure segment 5# after rotation. The lengths of the segments are 26m for the 0# segment, 31.5m for the 1# - 3# segments, 35m for the 4# segment, 2.5m for the closure segment 6#, and 4.55m for the cast-in-place segment 5# at the side pier.

[0089] For the rotated beam segment, first, the support piles and the foundation of the support are constructed parallel to the railway direction on the slope between the existing Beitongpu Railway and Zhongshe Reservoir. After the steel pipe support columns and the disk buckle scaffolds are erected and the main beam is cast in place and the cables are hung, it is then rotated clockwise by 32 degrees to be connected and closed with the cast-in-place segments at both side piers. The location of the cast-in-place beam of the main bridge is long-term soaked by the reservoir water, with a high groundwater level and poor soil quality, and extremely weak bearing capacity. According to the design requirements, the overall design of the main bridge support is: support piles + reinforced concrete support foundation + 609 steel pipe support columns + double-row 56C I-beams + 1.5m Bailey beams + 14 I-beam distribution beams + disk buckle scaffolds + 14 I-beam cross beams.

[0090] Application effect:

[0091] For the cast-in-place beam steel columns of the cable-stayed rotated ladder bridge on the second bid section of the east extension of Xinyang Avenue in Yangqu, which crosses the Beitongpu Railway, this construction method is used for hoisting construction. It simplifies and makes more convenient the previous processes and methods, with simple operation. All construction workers operate on the ground, avoiding the danger brought by high-altitude operations. The number of personnel and machinery invested is reduced, avoiding the need for site leveling at one time, and reducing the intangible construction investment and construction cost. At the same time, the construction speed has also been improved, with good application effects, and it is advisable to continue research, optimization, and promotion.

Claims

1. Hoisting process of a quick hoisting sling for a cast-in-place beam steel column support, characterized in that The following steps are involved: Step 1: Construction preparation: Site preparation, steel column foundation construction, steel column material delivery, lifting equipment delivery, and material delivery acceptance; Step 2: Measure foundation elevation; After the concrete strip foundation is completed and before the steel columns are installed, the actual elevation of the strip foundation steel column installation position needs to be re-measured, and the elevation error should be less than 5mm; Step 3: Process the top surface of the foundation; Level the top surface of the foundation, clean the soil on the top surface of the foundation, and straighten the anchor steel bars; Step 4: Measure the length of the steel column; There are different degrees of deviation in the use of steel columns, and with the undulations of the terrain, the elevations of the top surfaces of the strip foundations at different locations are all different. However, the top surfaces of the steel columns must be adjusted to a horizontal plane to ensure the smooth subsequent construction of the Bailey beams and the buckle frames. Therefore, when installing the steel columns, the length of the steel columns needs to be adjusted according to the elevation of the foundation. After the steel columns are delivered to the site, the actual length of the steel columns is adjusted through the adjustment sections of the steel columns according to the elevation of the foundation and the control elevation of the top of the steel columns. Step 5: Make the sling; Based on the outer diameter of the steel column, the weight of the connecting flange of the steel column, and a safety factor of 1.2 times, and the shape of the spreader, it was calculated that the spreader should be made on-site using a t=20mm steel plate. The spreader should be semicircular in structure, with circular holes at both ends and a connecting lug in the middle. Step 6: Support the lifting machinery; A 25t truck crane is used for lifting and hoisting of steel columns. The site should be prepared in advance. When the truck crane is parked, all outriggers should be erected to ensure that the crane is on a horizontal surface. Sleepers must be placed under all outriggers. Step 7: Install the slings and spreaders; During hoisting, pass the lifting wire rope around the front end of the steel column to be installed and connect the lifting wire rope to the sling through the U-shaped clamp ring. Hang it on the hook of the truck crane. The wire rope wrapped around the front end of the steel column should be in close contact with the flange of the steel column. After the U-shaped clamp ring is installed, the U-shaped ring can move freely during the hoisting process. Step 8: Lift the steel column; When the lifting conditions are met, the steel column is lifted. When the crane is lifting, the wire rope is automatically tightened under the tension of the steel pipe's own weight, and together with the lifting device, it tightly holds the steel column and is then lifted. Step 9: Fix the steel columns; After the steel column is moved to the installation position, the crane is commanded to adjust the installation position of the steel column and ensure the verticality of the steel column. The installation workers install a magnetic level on the side wall of the steel column to determine the verticality of the steel column. The steel column is fine-tuned with a crowbar and a wedge-shaped steel plate to ensure the verticality of the steel column. After the adjustment is in place and meets the requirements, the anchor steel bars embedded in the foundation of the steel column are bent until they are tightly attached to the steel column and then welded together. After the anchor steel bars are connected, a template is installed around the bottom of the steel column base, and then the support is grouted and sealed with a support grouting material with an elevation of not less than C50 to ensure that there is no gap between the steel column and the base. Step 10: Unload the slings and spreaders; After the steel column is firmly fixed, loosen the hook of the car crane, manually pull the cable tied to the spreader, and slide the wire rope tied to the steel column down along the spreader hole of the steel column to release it, and the spreader falls freely to the ground; thus completing one lifting operation; If the actual elevation is remeasured and exceeds the elevation error, measures need to be taken in advance to treat the concrete surface of the steel column foundation. If the concrete surface elevation is uneven or exceeds the allowable error value, the concrete surface needs to be chiseled off, or steel columns that can meet the actual construction needs are made to cope with the actual support column foundation elevation. If the top elevation of the strip foundation is low, self-compacting concrete pouring, steel plate padding, or steel columns of equivalent length can be made according to the actual elevation.

2. The hoisting process of a quick hoisting sling for a cast-in-place beam steel column support according to claim 1, characterized in that, The manual pulling of the cable tied to the sling can reduce the angle between the cable and the steel column as much as possible when the cable tied to the sling is pulled down, so that the steel column sling can be more easily separated from the steel column.

3. The hoisting process of a quick hoisting sling for a cast-in-place beam steel column support according to claim 1, characterized in that The diameter of the lifting wire rope is 20mm. If it is too thick or too thin, it will be difficult to lift. If it is too thick, the wire rope will be easily stuck by the clamp and difficult to remove; if it is too thin, the safety factor is not high and it is easy to break.

4. The hoisting process of a quick hoisting sling for a cast-in-place beam steel column support according to claim 1, characterized in that, The width of the site treatment should be at least one meter wider than the width of the truck crane legs. If it is backfill soil, the original site should be excavated at least 30 cm and then leveled and compacted. After the treatment is completed, a 30 cm thick layer of crushed stone should be laid, or a 20 cm thick layer of hardened C20 concrete should be added to improve the bearing capacity of the site foundation.

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