Outer-frame-free protection construction method for roof parapet wall of super high-rise building and application of outer-frame-free protection construction method

Abstract

The invention provides an outer frame-free protection construction method for a roof parapet wall of a super high-rise building and application, and belongs to the technical field of building construction.The outer frame-free protection construction method comprises the steps that S1, structural steel columns and steel beams are hoisted, floor support plates are laid, studs are welded to the tops of the steel beams to fix the floor support plates, and bolts are welded to the side faces of the steel columns to install steel wire ropes; s2, mounting floor support plate transverse steel bars and parapet wall vertical steel bars; s3, floor support plate concrete is poured; s4, binding a lower part, namely a parapet wall horizontal bar; s5, a safety belt is tied through a steel wire rope, and the lower parapet wall inner formwork and the lower parapet wall outer formwork are installed and reinforced in a segmented mode; s6, pouring concrete at the lower part of the parapet wall; s7, the lower formwork of the parapet wall is dismantled, and upper horizontal ribs of the parapet wall are installed; s8, an upper parapet wall formwork is installed and reinforced in the step S5; s9, concrete on the upper portion of the parapet wall is poured, and the formwork is dismantled; the outer-frame-free layered and segmented construction method is originally created, safety measures are taken by preassembling steel wire ropes, and the high-altitude parapet wall construction problem is solved in cooperation with a specific formwork system and a specific construction sequence.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, specifically to a method and application for constructing a parapet wall on the roof of a super high-rise building without external scaffolding. Background Technology

[0002] With the rapid development of urban society and economy, super high-rise buildings are increasingly common in modern urban construction. Steel frame-core tube structures, in particular, are widely used in commercial complexes, office buildings, and other projects due to their excellent seismic performance and spatial flexibility. These buildings typically feature parapet walls approximately 1.5 meters high along the edge of their outer roof panels, serving both safety and architectural aesthetic purposes. A parapet wall is a low wall extending above the roof surface around the perimeter of a building's roof, balcony, or terrace. It is part of the building structure and primarily serves protective, waterproof, and decorative functions. However, due to their high location, sometimes exceeding 150 meters above the ground, the construction of parapet walls presents significant safety challenges and technical difficulties.

[0003] Traditional construction methods often employ cantilevered I-beams in conjunction with modular scaffolding for external formwork support and work platform erection. This method not only requires the pre-embedding of numerous I-beams and the construction of a complex scaffolding structure, but also suffers from long construction periods, large material consumption, and high costs. Furthermore, the bottom of the external formwork is difficult to effectively reinforce during high-altitude operations, resulting in poor formwork stability and high construction risks, especially when pouring concrete for ultra-high, cantilevered structures, where the construction difficulty is further exacerbated.

[0004] Therefore, how to avoid using traditional external scaffolding, simplify the construction process, and reduce costs and time while ensuring construction safety and quality has become an urgent technical problem to be solved in the construction of parapet walls of super high-rise buildings. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to address the shortcomings of existing technologies by providing a method and application for constructing parapet walls on the roofs of high-rise buildings without external scaffolding. It features a unique method of construction without external scaffolding and in a layered and segmented manner, using pre-installed steel wire ropes for safety measures, and combining a specific formwork system and construction sequence to solve the challenges of constructing parapet walls at heights.

[0006] Technical solution: The present invention provides a method for constructing a parapet wall protection system for high-rise buildings without external scaffolding, comprising the following steps: S1. Hoist the structural steel columns and beams, lay the floor decking, weld studs on the top of the structural steel beams to fix the floor decking, weld bolts on the sides of the structural steel columns and install steel wire ropes; the structural steel columns are vertically installed at the intersection of the building's outer frame axes, and the structural steel beams are horizontally hoisted and connected between two structural steel columns or between the embedded parts of the structural steel columns and the core tube; the floor decking is laid on the upper surface of the structural steel beams, covering the entire frame area; Step S1 first constructs the building's permanent steel frame (composed of steel columns and beams), which forms the foundational load-bearing system for all subsequent construction. Laying floor slabs creates a solid working surface at height. Welding studs onto the steel beams ensures that the steel beams and concrete slabs can share the load after concrete is poured, greatly enhancing the rigidity and strength of the floor slab. Installing steel wire ropes on the sides of the steel columns provides a permanent safety rope anchor point for all subsequent high-altitude operations, replacing the safety railings of traditional scaffolding.

[0007] S2. Install horizontal reinforcing bars evenly distributed on the floor slab and vertical reinforcing bars evenly distributed on the parapet wall; the vertical reinforcing bars pre-inserted into the parapet wall form the main load-bearing reinforcement and preliminary skeleton of the parapet wall; the dense vertical reinforcing bars can also temporarily serve as guardrails before concrete pouring to prevent people from falling.

[0008] S3. Pour concrete for the floor deck; by pouring concrete, the floor deck, transverse reinforcement and studs are combined into a solid whole.

[0009] S4. Tie the horizontal reinforcement bars of the parapet wall at the first predetermined height; tie horizontally distributed reinforcement bars on the already anchored vertical reinforcement bars to form the reinforcement mesh of the lower half of the parapet wall, which bears the lateral force of the concrete in this part. Dividing the 1.5m high wall into two sections (750mm each) for construction significantly reduces the lateral pressure on the formwork each time concrete is poured, and solves the problem of formwork bulging and difficulty in reinforcement caused by pouring too high at once.

[0010] S5. Construction workers attach safety belts to steel wire ropes and install and reinforce the inner and outer formwork of the parapet wall at the first predetermined height in sections. Due to the obstruction of the erected vertical reinforcing bars, the entire large formwork cannot be inserted. It is divided into small formwork sections of 2 meters each, which can be flexibly inserted and assembled through the gaps in the reinforcing bars.

[0011] S6. Pour concrete for the parapet wall at the first predetermined height; pour concrete into the reinforced lower half of the formwork to form the lower half of the parapet wall. The solidified lower half of the wall can serve as the foundation and support for the upper construction.

[0012] S7. Remove the parapet wall formwork at the first predetermined height and install the upper parapet wall horizontal reinforcement 62 at the second predetermined height; after the lower concrete reaches its strength, remove its formwork for reuse, and extend and tie the upper part of the horizontal distribution reinforcement on the lower wall reinforcement.

[0013] S8. Install and reinforce the parapet wall formwork at the second predetermined height in the same manner as in step S5; S9. Pour concrete for the parapet wall at the second predetermined height, and finally remove all formwork.

[0014] Furthermore, the total height of the parapet wall is 1.5m, with both the first and second predetermined heights being 750mm. The 750mm height makes it very convenient for workers to stand on the floor slab to tie the reinforcing bars and install the formwork, which is ergonomic and improves work efficiency.

[0015] Furthermore, in steps S5 and S8, the length of each segment of the template installed in sections is 2m.

[0016] Furthermore, the specifications for the vertical reinforcement bars of the parapet wall are HRB400 Φ12, spaced at 200mm, and the length of their bottom anchorage into the roof floor slab 3 is not less than La. La is the anchorage length of the tension reinforcement in drawing 22G101. The specific value of La does not need to be calculated on-site, but is determined by referring to the relevant tables in the National Building Standard Design Drawing Atlas "22G101-1" (Drawing Rules and Construction Details for Overall Plan Representation of Concrete Structure Construction Drawings).

[0017] Furthermore, the specifications for the horizontal reinforcement bars of the parapet wall are HRB400 Φ8, with a spacing of 200mm.

[0018] Furthermore, in steps S5 and S8, the parapet wall formwork system includes 15mm thick plywood 63, 40*90mm timber 64, M14 tie rods 65, and Ф48*2.7 double steel pipe back bracing; the timber spacing is 200mm, and the double steel pipe back bracing spacing is 600mm.

[0019] Furthermore, during the installation and reinforcement of the upper parapet wall formwork in step S8, Ф48*2.7 diagonal braces are erected, and these braces are connected to the double steel pipe back braces via steel pipe fasteners. Because the bottom of the upper formwork is supported on the newly poured lower wall, its center of gravity is relatively high, and the diagonal braces can effectively prevent the formwork from overturning and the upper part from shifting. Application of a construction method for parapet wall protection without external scaffolding in super high-rise buildings with steel frame-core tube structure.

[0020] Beneficial effects: Compared with the prior art, the advantages of the present invention are as follows: This invention is applicable to steel frame-core tube super high-rise buildings. It eliminates the need for traditional cantilevered I-beam disc-lock scaffolding and allows for the completion of reinforced concrete construction of the 1.5m parapet wall at the edge of the cantilevered slab in sections and layers. This shortens the construction period, saves on the cost of pre-embedded I-beams and scaffolding erection, and ensures safety for high-altitude operations by installing steel wire ropes between the structural steel columns. At the same time, the parapet wall formwork, timber, and steel pipes have a high turnover rate, are environmentally friendly, meet the requirements of green construction, and are economical. Attached Figure Description

[0021] Figure 1 This is a schematic plan of a super high-rise building with a steel frame-core tube structure in this invention; Figure 2 This is a construction schematic diagram of the lower first predetermined height portion of the construction method in this invention; Figure 3 This is a construction diagram of the upper second predetermined height portion of the construction method in this invention. Detailed Implementation

[0022] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the embodiments described.

[0023] like Figure 1 As shown, the core tube 1 is typically located at the center of the building plan and is the main lateral force resisting component of a high-rise building. It usually contains elevator shafts, stairwells, and equipment / pipe shafts, and is surrounded by an outer frame structure. This outer frame structure typically consists of structural steel columns 4 arranged around the perimeter and structural steel beams 2 connecting these columns, working together with the core tube to bear the load. Construction workers work outwards from the core tube 1, fixing one end of the structural steel beam 2 to the core tube and the other end to the structural steel column 4. This creates a cantilevered working area extending outwards from the core tube and inner ring structure at high altitude. Additionally, a set of studs 7 are arranged along the centerline of the top surface of the structural steel beam 2 or at the design-required intervals. like Figure 2 and Figure 3 As shown, the parapet wall mainly consists of the following components, which can be divided into a panel system, secondary joists, main joists, a tie system, a support system, and a safety system. The panel system includes... Figure 2 and Figure 3 The main formwork consists of a wooden formwork 63, which directly contacts the concrete to form the parapet wall's design shape and surface flatness. Secondary joists (timber beams 64) support the formwork 63, evenly transferring the lateral pressure of the concrete to the main joists; their arrangement is perpendicular to the formwork 63. The main joists (steel pipe back braces 66) serve as the primary load-bearing components, bearing the concentrated loads transmitted from the secondary joists and maintaining the overall stability of the formwork system through a tie system. The tie system (tie rods 65) is the core component connecting the inner and outer formwork sides, preventing bulging or bursting of the formwork under the lateral pressure of the concrete. The support system (diagonal braces 67) is used only for the upper 750mm of the formwork, providing diagonal support to prevent the top of the formwork from overturning or shifting due to pouring impact or wind. The safety system (steel wire ropes 5) is used for workers to wear safety belts when installing and reinforcing the formwork.

[0024] A method for constructing a parapet wall on the roof of a high-rise building without external scaffolding includes the following steps: S1. Hoist the structural steel columns 4 and structural steel beams 2, lay the floor decking 3, weld studs 7 on the top of the structural steel beams 2 to fix the floor decking 3, weld bolts on the side of the structural steel columns 4 and install steel wire ropes 5; the structural steel columns 4 are vertically installed at the intersection of the axes of the building's outer frame, the structural steel beams 2 are horizontally hoisted and connected between two structural steel columns 4 or between the embedded parts of the structural steel columns 4 and the core tube 1; the floor decking 3 is laid on the upper surface of the structural steel beams 2, covering the entire frame area; S2. Install horizontal reinforcing bars evenly distributed on the floor slab and vertical reinforcing bars evenly distributed on the parapet wall 61; S3. Pour concrete for the floor deck slab; S4. Tie the horizontal steel bars of the parapet wall at the first predetermined height at the bottom, 62mm; S5. Construction workers attach safety belts to steel wire rope 5 and install and reinforce the inner and outer formwork of the parapet wall at the first predetermined height in sections. S6. Pour concrete for the parapet wall at the first predetermined height; S7. Remove the parapet wall formwork at the first predetermined height and install the upper parapet wall horizontal reinforcement 62 at the second predetermined height; S8. Install and reinforce the parapet wall formwork at the second predetermined height in the same manner as in step S5; S9. Pour concrete for the parapet wall at the second predetermined height, and finally remove all formwork.

[0025] In this embodiment, the total height of the parapet wall 6 is 1.5m, and both the first predetermined height and the second predetermined height are 750mm. In steps S5 and S8, the length of each segment of the template installed is 2m. The specifications of the vertical reinforcing bars 61 of the parapet wall are HRB400 Φ12, with a spacing of 200mm, and the length of their bottom anchored into the roof floor slab 3 is not less than La. The specifications of the horizontal reinforcing bars 62 of the parapet wall are HRB400 Φ8, with a spacing of 200mm. In steps S5 and S8, the parapet wall template system includes 15mm thick plywood 63, 40*90mm timber 64, M14 tie rods 65, and Ф48*2.7 double steel pipe back braces 66; the spacing of the timber 64 is 200mm, and the spacing of the double steel pipe back braces 66 is 600mm. When installing the upper parapet wall formwork in step S8, it is also necessary to support the Ф48*2.7 diagonal brace 67. The diagonal brace 67 is connected to the double steel pipe back brace 66 through steel pipe fasteners.

[0026] As described above, although the invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the invention itself. Various changes in form and detail may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A method for constructing a parapet wall on the roof of a super high-rise building without external scaffolding, characterized in that... Includes the following steps: S1. Hoist the structural steel columns (4) and structural steel beams (2), lay the floor decking (3), weld studs (7) on the top of the structural steel beams (2) to fix the floor decking (3), weld bolts on the side of the structural steel columns (4) and install steel wire ropes (5); the structural steel columns (4) are vertically installed at the intersection of the axes of the building's outer frame, the structural steel beams (2) are horizontally hoisted and connected between the two structural steel columns (4) or between the embedded parts of the structural steel columns (4) and the core tube (1); the floor decking (3) is laid on the upper surface of the structural steel beams (2) to cover the entire frame area; S2. Install horizontal reinforcing bars evenly distributed on the floor deck and vertical reinforcing bars evenly distributed on the parapet wall (61). S3. Pour concrete for the floor deck slab; S4. Tie the horizontal reinforcement bars (62) of the parapet wall at the first predetermined height at the bottom. S5. Construction workers fasten safety belts to the steel wire rope (5) and install and reinforce the inner and outer formwork of the parapet wall at the first predetermined height in sections. S6. Pour concrete for the parapet wall at the first predetermined height; S7. Remove the parapet wall formwork at the first predetermined height and install the upper parapet wall horizontal reinforcement (62) at the second predetermined height. S8. Install and reinforce the parapet wall template of the second predetermined height in the same manner as in step S5; S9. Pour concrete for the parapet wall at the second predetermined height, and finally remove all formwork.

2. The method for constructing a parapet wall protection system for a super high-rise building without external scaffolding, as described in claim 1, is characterized in that: The total height of the parapet wall (6) is 1.5m, and the first predetermined height and the second predetermined height are both 750mm.

3. A method for constructing a parapet wall protection system for a super high-rise building without external scaffolding, as described in claim 1, is characterized in that: In steps S5 and S8, the length of each segment of the template to be installed is 2m.

4. A method for constructing a parapet wall protection system for a super high-rise building without external scaffolding, as described in claim 1, is characterized in that: The specifications of the vertical steel bars (61) of the parapet wall are HRB400 Φ12 with a spacing of 200mm, and the length of their bottom anchored into the roof floor slab (3) is not less than La.

5. A method for constructing a parapet wall protection system for a super high-rise building without external scaffolding, as described in claim 1, characterized in that: The specifications of the horizontal steel bars (62) of the parapet wall are HRB400 Φ8, with a spacing of 200mm.

6. A method for constructing a parapet wall protection system for a super high-rise building without external scaffolding, as described in claim 1, characterized in that: In steps S5 and S8, the parapet wall formwork system includes 15mm thick plywood (63), 40*90mm timber (64), M14 tie rods (65), and Ф48*2.7 double steel pipe back bracing (66); the spacing of the timber (64) is 200mm, and the spacing of the double steel pipe back bracing (66) is 600mm.

7. A method for constructing a parapet wall protection system for a super high-rise building without external scaffolding, as described in claim 1, characterized in that: When installing the upper parapet wall formwork in step S8, a Ф48*2.7 diagonal brace (67) is erected. The diagonal brace (67) is connected to the double steel pipe back brace (66) through a steel pipe fastener.

8. Application of a construction method for parapet wall protection without external scaffolding in super high-rise buildings on steel frame-core tube structures.

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