Large-span steel truss hoisting method for protecting hollow floor structure

Abstract

The invention relates to a large-span steel truss hoisting method for protecting a hollow floor structure, and the specific construction method comprises the following steps: after concrete pouring of the hollow floor structure is completed, carrying out covering geotechnical cloth maintenance for not less than 7 days; the stress condition of a hollow floor is analyzed through finite elements, the walking route of a 50-ton truck-mounted crane is planned to be fully paved on a roadbed box, the joint positions of the four end faces of the roadbed box need to fall on the center line of a rib beam, and the two side edges of the roadbed box are arranged close to the center line of a main beam; a steel base plate is arranged between the end of a roadbed box and a concrete beam, it is ensured that the distance between the roadbed box and a concrete slab is not smaller than 10 mm, a position sensor is used for monitoring at any time, and it is ensured that the deflection of the roadbed box is not larger than 10 mm; and the truck crane hoists the steel truss roof component on the roadbed box of the walking route. The method belongs to the technical field of large-span steel truss hoisting construction, the roadbed box and finite element analysis are combined, concentrated loads are conducted to a main stress structure, and a hollow floor structure is effectively protected against crushing damage during hoisting.

Description

Technical Field

[0001] This application relates to the field of large-span steel truss hoisting construction technology, and in particular to a method for hoisting large-span steel trusses to protect hollow floor structures. Background Technology

[0002] Hollow core slabs are an advanced building technology. With the progress of modern society and the improvement of people's living standards, public buildings and residential buildings are increasingly trending towards larger spans, wider openings, and heavier loads to meet users' needs for flexible layout, convenient decoration, and multifunctional use. The emergence of hollow core slabs has solved the contradiction between structure and construction in cast-in-place concrete floor slabs, effectively meeting the technical requirements of large spans, large spaces, heavy loads, and flexible layouts that traditional building structures cannot satisfy. They are widely applicable to large-span buildings such as office buildings, warehouses, factories, underground garages, large shopping malls, school buildings, and libraries.

[0003] However, this is the first time that hollow floor slab technology has been applied in railway engineering. A series of issues need to be further studied and determined, including the combination of its unique structural mode with the traditional grid beam floor slab, the anti-buoyancy measures of the filling material during the concrete pouring process, and even whether the hollow floor slab area can meet the load-bearing requirements when used as a construction platform for the upper large-span steel truss roof. Summary of the Invention

[0004] Therefore, it is necessary to provide a method for hoisting large-span steel trusses to protect hollow floor slab structures, and the specific technical solution is as follows.

[0005] A method for hoisting a large-span steel truss to protect a hollow floor structure, the specific construction method including: S1. Erecting formwork and laying templates; S2. Tie the reinforcing bars of the rib beam and the bottom plate on the template, place the hollow box on the bottom plate, set the anti-buoyancy support at the top of the hollow box, and tie the top plate reinforcing bars connected to the rib beam and the anti-buoyancy support above it. S3. The hollow floor slab concrete is poured in layers. The thickness of the first layer of concrete is between one-third and one-half of the total thickness of the hollow floor slab structure. The remaining concrete is poured before the first layer of concrete sets. The time interval between pouring is 80 to 100 minutes. S4. After the concrete pouring of the hollow floor slab structure is completed, it shall be covered with geotextile for curing for no less than 7 days. S5. Analyze the stress on the hollow floor slab using the finite element method, plan the travel route of the 50-ton truck crane, and mark the center lines of the rib beams and the main beams on the top surface of the hollow floor slab. S6. The roadbed boxes are fully laid along the planned walking route. The joint positions of the four end faces of the roadbed boxes must fall on the center line of the rib beam, and the two sides of the roadbed boxes are set close to the center line of the main beam. S7. Install steel pads between the end of the roadbed box and the concrete beam to ensure that the distance between the roadbed box and the concrete slab is not less than 10mm. Use position sensors to monitor at all times to ensure that the deflection of the roadbed box is not greater than 10mm. S8. The truck crane lifts the steel truss roof components from the roadbed box along the travel route.

[0006] Furthermore, in step S2 above, the anti-buoyancy support is tied to the rib beam reinforcement and the top plate reinforcement with wire, and the downward pressure provided by the rib beam reinforcement and the top plate reinforcement is applied to the hollow box body. When the hollow floor slab concrete is poured in layers, the total thickness of the hollow floor slab structure is 700mm, and the thickness of the first layer of concrete is 300mm.

[0007] Furthermore, the anti-buoyancy support includes a pressure plate, an upright, and a diagonal brace. The upright is vertically mounted on the pressure plate, and the bottom of the diagonal brace is provided with a sleeve that is slidably connected to the upright. The diagonal brace can be adjusted up and down and rotated left and right to abut against the top plate reinforcement, and then the sleeve is fixed to the upright.

[0008] Furthermore, in step S5 above, a roadway is laid using roadbed boxes near the center line of the main beam. The roadway is set close to the center line of the main beam and is no less than 4 meters wide. Temporary warning lines are set on both sides of the roadway, and vehicles travel in the designated route area.

[0009] Furthermore, in step S6 above, the construction method for laying roadbed boxes under the lifting area of ​​the truck crane is as follows: red paint lines are used to mark the positions of the corresponding rib beams on the hollow floor slab, and the specifications of the roadbed boxes are set to 2m x 5m x 0.2m. The ends of the roadbed boxes are laid on the lines marked with red paint.

[0010] Furthermore, in step S7 above, a steel pad with a specification of 14*200*2000mm is set between the end of the roadbed box and the concrete beam, and adjacent roadbed boxes are connected by welding.

[0011] Furthermore, a long steel plate is installed on the concrete beam of the hollow floor slab between two rib beams. The two ends of the long steel plate are supported on the main beam. A hydraulic jack is installed on the long steel plate to support the roadbed box. The hydraulic cylinder of the hydraulic jack is connected to the oil tank through an oil pipe and an oil pump. A solenoid valve electrically connected to the controller is installed on the oil pipe.

[0012] Furthermore, when the position sensor detects that the distance between the bottom surface of a roadbed box and the floor slab is less than 10mm, it sends a signal to the controller. The controller then sends a signal to open the corresponding solenoid valve, causing the hydraulic jack to rise and support the roadbed box.

[0013] Furthermore, in step S8 above, the specific construction method for hoisting the steel truss roof components is as follows: the steel roof steel columns and the commercial mezzanine steel columns are hoisted at the 9.75m floor level using a 50t truck crane. First, the steel roof steel columns are hoisted in three or four sections nearby, and then the commercial mezzanine steel columns are hoisted as a whole nearby.

[0014] Furthermore, the steel column hoisting adopts a 4-point hoisting method. The appropriate steel wire rope is selected based on the weight of the component. The length of the steel wire rope must ensure that the included angle between the ropes is not greater than 60° after the steel column is tied.

[0015] Compared with existing technologies, the present invention has the following advantages: This invention provides a method for hoisting large-span steel truss structures to protect hollow floor slabs. It offers several advantages: reliable anti-buoyancy design; precise positioning of the hollow box structure thanks to the dual protection of layered casting and anti-buoyancy supports; optimized load distribution by combining roadbed boxes and finite element analysis to transfer concentrated loads to the main load-bearing structure, effectively protecting the hollow floor slab structure from damage during hoisting; intelligent monitoring with position sensors and hydraulic jacks for real-time load adjustment to prevent structural damage; and high construction efficiency through segmented hoisting and multi-point design to shorten the construction period and reduce safety risks. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the arrangement of the roadbed boxes in this invention; Figure 2 This is a schematic diagram of the layout of the travel path of the truck crane in this invention; Figure 3 This is a construction schematic diagram of the hollow box body in this invention; Figure 4 This is a schematic diagram of the anti-buoyancy support structure in this invention.

[0018] Explanation of reference numerals in the attached figures: 1. Formwork support; 2. Template; 3. Rib reinforcement; 4. Bottom slab reinforcement; 5. Hollow box; 6. Anti-buoyancy support; 7. Top slab reinforcement; 8. Roadbed box; 9. Pressure plate; 10. Upright; 11. Diagonal brace; 12. Main beam; 13. Hydraulic jacking rod; 14. Steel pad; 15. Rib. Detailed Implementation

[0019] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0020] The embodiments of the present invention will now be described.

[0021] Reference Figures 1-4 As shown, this embodiment provides a method for hoisting a large-span steel truss to protect a hollow floor slab structure. The specific construction method includes: S1. Erect the formwork support 1 and lay the template 2; S2. Tie the rib beam reinforcement 3 and bottom plate reinforcement 4 on the template 2. Place the hollow box 5 on the bottom plate reinforcement 4. Set the anti-buoyancy support 6 at the top of the hollow box 5 and tie the top plate reinforcement 7 connected to the rib beam reinforcement 3 and anti-buoyancy support 6 above it. S3. The hollow floor slab concrete is poured in layers. The thickness of the first layer of concrete is between one-third and one-half of the total thickness of the hollow floor slab structure. The remaining concrete is poured before the first layer of concrete sets. The time interval between pouring is 80 to 100 minutes. S4. After the concrete pouring of the hollow floor slab structure is completed, it shall be covered with geotextile for curing for no less than 7 days. S5. Analyze the stress on the hollow floor slab using finite element method, plan the travel route of the 50-ton truck crane, and mark the center lines of the rib beam 15 and the main beam 12 on the top surface of the hollow floor slab. S6. The roadbed box 8 is fully laid on the planned walking route. The joint positions of the four end faces of the roadbed box 8 must fall on the center line of the rib beam, and the two sides of the roadbed box 8 are set close to the center line of the main beam. S7. Install steel pads between the 8th end of the roadbed box and the concrete beam to ensure that the distance between the roadbed box and the concrete slab is not less than 10mm. Use position sensors to monitor at all times to ensure that the deflection of the roadbed box is not greater than 10mm. S8. The truck crane lifts the steel truss roof components on the roadbed box 8 of the travel route.

[0022] In the method for hoisting a large-span steel truss to protect a hollow floor slab structure according to the present invention, a formwork support 1 is erected and a template 2 is laid; rib beam reinforcement 3 and bottom plate reinforcement 4 are tied, a hollow box 5 is placed and an anti-buoyancy support 6 is set; the first layer of concrete is poured in layers of 300mm, with a total thickness of 700mm, and the remaining pouring is completed before initial setting; the concrete is covered with geotextile and cured for ≥7 days. By pouring concrete in layers, the buoyancy effect of the concrete on the hollow box slab is reduced. The anti-buoyancy support 6 uses the downward pressure of the rib beam reinforcement 3 and the top plate reinforcement 7 to fix the hollow box slab 5, preventing displacement, solving the anti-buoyancy problem of the hollow box slab during the pouring process, ensuring the compactness and load-bearing capacity of the floor slab structure, avoiding concrete voids caused by the floating of the hollow box slab, and improving the integrity and durability of the floor slab.

[0023] Finite element analysis of the floor slab stress was used to mark the center lines of the rib beams and main beams; the roadbed box 8, with a specification of 2m×5m×0.2m, was fully laid, with the joints located at the center line of the rib beams and the sides close to the main beams; steel pads 14 and position sensors were installed to control the deflection of the roadbed box to ≤10mm; the roadbed box 8 distributed the load of the truck crane to the rib beams and main beams 12, and the steel pads 14 and hydraulic jacks 13 dynamically adjusted the height of the roadbed box, with sensors monitoring the deflection in real time; the hollow floor slab was protected from damage by concentrated loads to ensure hoisting safety; local stress in the floor slab was reduced to prevent cracking; and automated monitoring improved construction accuracy.

[0024] A 50t truck crane was used to lift 3-4 sections of the steel roof column and the entire commercial mezzanine column in sections on the roadbed box 8. The sectioned lifting reduced the load per lift, enabling efficient and safe lifting of large-span steel trusses, reducing the risk of lifting deformation, and improving construction efficiency.

[0025] Specifically, in step S2 above, the anti-buoyancy support 6 is tied to the rib beam reinforcement 3 and the top plate reinforcement 7 with iron wire. The downward pressure provided by the rib beam reinforcement 3 and the top plate reinforcement 7 is applied to the hollow box body 5. When the hollow floor slab concrete is poured in layers, the total thickness of the hollow floor slab structure is 700mm, and the thickness of the first layer of concrete is 300mm.

[0026] Specifically, the anti-buoyancy support 6 includes a pressure plate 9, an upright 10, and diagonal braces 11. The upright 10 is vertically mounted on the pressure plate 9. The bottom of the diagonal brace 11 is provided with a sleeve that is slidably connected to the upright 10. The diagonal brace 11 can be adjusted vertically and rotated horizontally to abut against the top plate reinforcement 7, and then the sleeve is fixed to the upright 10. The anti-buoyancy support 6 includes a pressure plate 9, an upright 10, and diagonal braces 11. The diagonal braces are adjustable and fixed to the top plate reinforcement 7. The angle and height of the diagonal braces 11 are adjusted by sliding the sleeve to form a stable support system, enhancing the adaptability and fixing effect of the anti-buoyancy support, flexibly adapting to different reinforcement arrangements, and ensuring zero displacement of the hollow box.

[0027] Specifically, in step S5 above, a roadway is laid using roadbed boxes 8 near the center line of the main beam. The roadway is set close to the center line of the main beam and is no less than 4 meters wide. Temporary warning lines are set on both sides of the roadway, and vehicles travel in the designated route area.

[0028] Specifically, in step S6 above, the construction method for laying the roadbed box 8 under the lifting area of ​​the truck crane is as follows: use red paint to mark the position of the corresponding rib beam on the hollow floor slab, set the specifications of the roadbed box 8 to be 2m x 5m x 0.2m, and lay the end of the roadbed box 8 on the marked line.

[0029] Specifically, in step S7 above, a steel pad 14 with dimensions of 14*200*2000mm is installed between the end of the roadbed box 8 and the concrete beam, and adjacent roadbed boxes 8 are connected by welding. The roadbed box 8 distributes the load of the truck crane to the rib beam and main beam 12. The steel pad 14 and hydraulic jack 13 dynamically adjust the height of the roadbed box. The thickness of the steel pad 14 is 14mm, and sensors monitor the deflection in real time; this protects the hollow floor slab from damage by concentrated loads and ensures hoisting safety; it reduces local stress in the floor slab and prevents cracking; and automated monitoring improves construction accuracy.

[0030] Specifically, a long steel plate is installed on the concrete beam of the hollow floor slab between two rib beams. The two ends of the long steel plate are supported on the main beam 12. A hydraulic jack 13 supporting the roadbed box 8 is installed on the long steel plate. The hydraulic cylinder of the hydraulic jack 13 is connected to the oil tank through an oil pipe and an oil pump. A solenoid valve electrically connected to the controller is installed on the oil pipe.

[0031] Specifically, when the position sensor detects that the distance between the bottom surface of a roadbed box 8 and the floor slab is less than 10mm, it sends a signal to the controller. The controller then sends a signal to open the corresponding solenoid valve, causing the hydraulic jack 13 to rise and support the roadbed box 8. The hydraulic jack 13 is linked to the solenoid valve and the controller. The sensor triggers the jacking to maintain the distance between the roadbed box 8 and the floor slab ≥ 10mm. The closed-loop control system adjusts the height of the hydraulic jack in real time to compensate for the deflection of the roadbed box; dynamically balances the load to prevent the floor slab from exceeding the limit deformation; and automated support improves safety and construction stability.

[0032] Specifically, in step S8 above, the specific construction method for hoisting the steel truss roof components is as follows: the steel roof steel columns and the commercial mezzanine steel columns are hoisted at the 9.75m floor level using a 50t truck crane. First, the steel roof steel columns are hoisted in three or four sections nearby, and then the commercial mezzanine steel columns are hoisted as a whole nearby.

[0033] Specifically, the steel column hoisting adopts a 4-point hoisting method. Appropriate steel wire ropes are selected based on the weight of the component, and the length of the wire ropes must ensure that the included angle between the ropes after the steel column is tied does not exceed 60°. Using the 4-point hoisting method, with the wire rope angle ≤60°, the force is evenly distributed across multiple hoisting points. Segmented hoisting reduces the single load, achieving efficient and safe hoisting of large-span steel trusses, reducing the risk of hoisting deformation, and improving construction efficiency.

[0034] Specific usage process Preliminary preparations: Erect formwork scaffolding 1, tie reinforcing bars 3-4-7, install hollow box 5 and anti-buoyancy support 6.

[0035] Concrete construction: Pour in layers of 300mm + 400mm, and cover and cure for 7 days.

[0036] Lifting plan: Finite element analysis to mark the route, and lay roadbed boxes 8 and steel pads 14.

[0037] Dynamic monitoring: Sensors control hydraulic jack 13 to maintain the levelness of the roadbed box.

[0038] Truss hoisting: The truck crane hoisted the steel columns in sections using the 4-point hoisting method to complete the roof construction.

[0039] The construction method of the present invention has the following advantages: Anti-buoyancy reliability: Layered casting + anti-buoyancy support 6 double protection hollow box body 5 precise positioning; Load distribution optimization: Combining the roadbed box 8 with finite element analysis, concentrated loads are transferred to the main load-bearing structure; Intelligent monitoring: Position sensors and hydraulic jacks 13 enable real-time load adjustment to avoid structural damage; Construction efficiency: Segmented hoisting and multi-point hoisting design shorten the construction period and reduce safety risks.

[0040] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0041] The above embodiments only illustrate one or more implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for hoisting a large-span steel truss to protect a hollow floor structure, characterized in that, Specific construction methods include: S1. Erect the formwork (1) and lay the template (2); S2. Tie the rib beam reinforcement (3) and bottom plate reinforcement (4) on the template (2), place the hollow box (5) on the bottom plate reinforcement (4), set the anti-buoyancy support (6) at the top of the hollow box (5) and tie the top plate reinforcement (7) connected to the rib beam reinforcement (3) and anti-buoyancy support (6) above it. S3. The hollow floor slab concrete is poured in layers. The thickness of the first layer of concrete is between one-third and one-half of the total thickness of the hollow floor slab structure. The remaining concrete is poured before the first layer of concrete sets. The time interval between pouring is 80 to 100 minutes. S4. After the concrete pouring of the hollow floor slab structure is completed, it shall be covered with geotextile for curing for no less than 7 days. S5. Analyze the stress on the hollow floor slab using the finite element method, plan the travel route of the 50-ton truck crane, and mark the center lines of the rib beams and the main beams on the top surface of the hollow floor slab. S6. The roadbed boxes (8) are fully laid on the planned walking route. The joint positions of the four end faces of the roadbed boxes (8) must fall on the center line of the rib beam. The two sides of the roadbed boxes (8) are set close to the center line of the main beam. S7. Install steel pads between the end of the roadbed box (8) and the concrete beam to ensure that the distance between the roadbed box and the concrete slab is not less than 10mm. Use position sensors to monitor at all times to ensure that the deflection of the roadbed box is not greater than 10mm. S8. The truck crane lifts the steel truss roof components on the roadbed box (8) of the travel route.

2. The method for hoisting a large-span steel truss to protect a hollow floor structure according to claim 1, characterized in that, In step S2 above, the anti-buoyancy support (6) is tied to the rib beam reinforcement (3) and the top plate reinforcement (7) with wire. The downward pressure provided by the rib beam reinforcement (3) and the top plate reinforcement (7) is applied to the hollow box (5). When the hollow floor slab concrete is poured in layers, the total thickness of the hollow floor slab structure is 700mm, and the thickness of the first layer of concrete is 300mm.

3. The method for hoisting a large-span steel truss to protect a hollow floor structure according to claim 2, characterized in that, The anti-buoyancy support (6) includes a pressure plate (9), a vertical pole (10) and a diagonal brace (11). The vertical pole (10) is vertically mounted on the pressure plate (9). The bottom of the diagonal brace (11) is provided with a sleeve that is slidably connected to the vertical pole (10). The diagonal brace (11) can be adjusted up and down and rotated left and right. After it abuts against the top plate reinforcement (7), the sleeve is fixed to the vertical pole (10).

4. The method for hoisting a large-span steel truss to protect a hollow floor structure according to claim 3, characterized in that, In step S5 above, a roadway is laid using a roadbed box (8) near the center line of the main beam. The roadway is set near the center line of the main beam and is no less than 4 meters wide. Temporary warning lines are set on both sides of the roadway, and vehicles travel in the designated route area.

5. The method for hoisting a large-span steel truss to protect a hollow floor structure according to claim 4, characterized in that, In step S6 above, the construction method for laying the roadbed box (8) under the lifting area of ​​the truck crane is as follows: use red paint to mark the position of the corresponding rib beam on the hollow floor slab, set the specifications of the roadbed box (8) to be 2m x 5m x 0.2m, and lay the end of the roadbed box (8) on the marked line.

6. A method for hoisting a large-span steel truss to protect a hollow floor structure according to any one of claims 1-5, characterized in that, In step S7 above, a steel pad with a specification of 14*200*2000mm is set between the end of the roadbed box (8) and the concrete beam, and the adjacent roadbed boxes (8) are connected by welding.

7. The method for hoisting a large-span steel truss to protect a hollow floor structure according to claim 6, characterized in that, A long steel plate is installed on the concrete beam of the hollow floor slab between two rib beams. The two ends of the long steel plate are supported on the main beam (12). A hydraulic jack (13) supporting the roadbed box (8) is installed on the long steel plate. The hydraulic cylinder of the hydraulic jack (13) is connected to the oil tank through an oil pipe and an oil pump. A solenoid valve electrically connected to the controller is installed on the oil pipe.

8. The method for hoisting a large-span steel truss to protect a hollow floor structure according to claim 7, characterized in that, When the position sensor detects that the distance between the bottom surface of a roadbed box (8) and the floor slab is less than 10mm, it sends a signal to the controller. The controller then sends a signal to open the corresponding solenoid valve, causing the hydraulic jack (13) to rise and support the roadbed box (8).

9. A method for hoisting a large-span steel truss to protect a hollow floor structure according to claim 6, characterized in that, In step S8 above, the specific construction method for hoisting the steel truss roof components is as follows: the steel roof steel columns and the commercial mezzanine steel columns are hoisted at the 9.75m floor level using a 50t truck crane. First, the steel roof steel columns are hoisted in three or four sections nearby, and then the commercial mezzanine steel columns are hoisted as a whole nearby.

10. The method for hoisting a large-span steel truss to protect a hollow floor structure according to claim 9, characterized in that, The steel column hoisting adopts a 4-point hoisting method. The appropriate steel wire rope is selected based on the weight of the component. The length of the steel wire rope must ensure that the included angle between the ropes is not greater than 60° after the steel column is tied.

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