A construction method for dismantling the cantilevered roof structure of a high-rise building

Abstract

The present invention discloses a construction method for dismantling the cantilevered structure of the roof of a high-rise building. The method is based on setting up an independent cantilevered platform, establishing a safe construction platform and facade safety protection, and realizing non-destructive cutting and demolition. In the case of complex construction environment, dense crowds, and limited lifting conditions in old urban areas, the construction platform uses I-beams as the main load-bearing components, and establishes a safe cutting operation platform and an edge protection system based on steel beams, realizing the integration of the workers' construction operation platform and the facade protection system. The steel platform is not directly connected to the original roof structure layer, does not cause damage to the residential house structure on the top floor of the building, and does not affect the daily life of the residents.

Description

Technical Field

[0001] The invention belongs to the technical field of high-rise building construction, and in particular relates to a construction method for dismantling an overhanging roof structure of a high-rise building. Background Art

[0002] The removal of the roof cantilever structure of high-rise buildings is done on the edge, which is difficult to construct and poses great safety hazards. Hoisting is difficult and requires high arm length and amplitude of the crane. In the old city, there are dense populations and narrow streets, and the conditions for erecting large lifting equipment are limited. Summary of the invention

[0003] In order to overcome the above-mentioned technical problems in the prior art, the present invention provides a construction method for dismantling the cantilevered structure of the roof of a high-rise building. The cantilevered construction platform provides a closed and safe construction site, ensuring the safety of workers during the construction process, minimizing the impact of the construction process on the daily life of residents in the renovated community, reducing the coordination work during the construction process, reducing the damage to the original structural layer of the roof, reducing the cost of roof restoration, and solving the above-mentioned technical problems.

[0004] A construction method for dismantling a cantilevered roof structure of a high-rise building, the construction method comprising the following construction steps:

[0005] S1: Hoist the prefabricated I-beams and steel pipes to the roof, drill holes in the roof parapet and provide ground protection;

[0006] S2: Use prefabricated main beams to build the main structure of the cantilever platform. Prefabricated I-beams are used to form a cantilever structure through the reserved holes of the parapet wall. The main beams in the longitudinal and transverse directions are arranged on two elevation surfaces. All longitudinal main beam I-beams are on the lower layer, and all transverse main beam I-beams are on the upper layer. The intersection of the longitudinal and transverse I-beams is connected and fixed by a U-shaped clamp with a diameter of 16mm, so that the longitudinal main beam I-beam and the transverse main beam I-beam cantilever structure platform are connected as a whole, and the I-beam is anchored to the roof shear wall to improve the overall platform stability, and the welding of the transverse beam and the longitudinal beam is completed;

[0007] S3: After the main beam passes the acceptance, the adjacent channel steel is connected with the cantilever section distribution beam. The adjacent channel steel and the distribution beam are installed manually with a truck crane. The cantilever section cross beam is connected to the I-beam through the main beam cantilever section connection plate. The main beam cantilever section connection plate is fixed to the cantilever section of the steel beam by welding at intervals of 0.4 meters. The distribution beam connection plate is fixed to both ends of the distribution beam by welding, and the cantilever section distribution beam is connected to the main beam by bolts;

[0008] S4: First, place the 3m×2.50m stamped steel plate horizontally on the cantilever beam that has been cantilevered and fixed. Workers stand on the stamped steel plate and fix the stamped steel plate on the steel beam with wire. After increasing the working surface, install the edge channel steel, and then exchange and move the stamped steel plates in turn to complete the installation of the edge channel steel, cantilever section distribution beam and patterned steel plate;

[0009] S5: Use the distribution beam connecting plate to connect the distribution beam with the main beam and fully cover it with patterned steel plates. Use self-tapping screws to fix the patterned steel plates and the crossbeams into one piece, so as to facilitate the removal and transfer after completion;

[0010] S6: Insert the vertical columns of the facade protection into the prefabricated seamless steel pipe support and fix them. Three horizontal cross bars are set in the middle. The wall connecting rods are connected and fixed with the original structural column clamps. The layout of the third horizontal cross bar is determined according to the height of the demolished structure and shall not be lower than the demolished structure. The waist bars are set according to the actual erection height. After the horizontal bars and waist bars are erected, a layer of steel plate mesh is set inside the erected facade protection frame;

[0011] S7: Use the wire rope of a truck crane or a small cantilever crane to stabilize the demolished concrete block. After the hook wire rope is tightened, use a rope saw to cut it. During the cutting process, the mass of the concrete block cut each time shall not exceed 500kg.

[0012] In the above-mentioned construction method for dismantling the cantilevered structure of the roof of a high-rise building, the prefabricated main beam in step S2 is customized according to the size of the roof of the high-rise building and the length of the cantilevered structure, the length of the cantilevered section needs to be 0.5m greater than the length of the cantilevered structure, and the height of the vertical pole in the facade protection system is 0.5m higher than the height of the cantilevered structure.

[0013] The cantilevered section is cantilevered outdoors. Each cantilevered section is a group of two. Before pushing outward from the hole, tie a traction rope at the end and hang one end of the anti-fall safety net. When pushing outward, the traction rope and the safety net are released simultaneously. After the cantilever is in place, tighten the safety net to form a safety protection. After the fixed installation of the internal section is completed, the platform beam can be installed.

[0014] When cantilever I-beams are manufactured, pre-installed vertical protection supports are installed at the ends. The vertical protection columns are made of round steel pipes that are inserted into the reserved supports and fixed. The horizontal bars are connected to the columns using cross fasteners. Three horizontal bars are set and waist bars are added. After the horizontal bars and waist bars are erected, the steel plate mesh is laid to complete the vertical protection.

[0015] In the above-mentioned construction method for dismantling the cantilevered roof structure of a high-rise building, in step S2, the prefabricated main beam is fixed to the shear wall through the shear wall connecting plate of the distribution room and chemical bolts, the shear wall connecting plate reserves 6 anchor points and is circumferentially welded to the end side of the I-beam, and the shear wall and the I-beam are fixed together by chemical bolts.

[0016] In the above-mentioned construction method for dismantling the cantilevered roof structure of a high-rise building, before cutting the concrete block in step S7, carbon fiber cloth is used for reinforcement, the carbon fiber cloth is arranged throughout the length and the overlap length is not less than 100 mm, the thickness of the primer does not exceed 0.4 mm, and after the carbon fiber cloth is pasted, the curing and curing time shall not be less than 3 days.

[0017] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0018] 1. The present invention provides a construction method for dismantling the cantilevered structure of a high-rise building roof. The cantilevered construction platform provides a closed and safe construction site, ensures the safety of workers during the construction process, minimizes the impact of the construction process on the daily life of residents in the renovation community, and reduces the coordination work during the construction process;

[0019] 2. This construction method reduces the damage to the original structural layer of the roof and reduces the cost of roof restoration. The main components are prefabricated in the factory for easy turnover, reducing resource input and material consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings, wherein:

[0021] Figure 1 It is a front view of the connection between the I-beam and the shear wall of the present invention;

[0022] Figure 2 It is a side view of the connection between the I-beam and the shear wall of the present invention;

[0023] Figure 3 This is a schematic diagram of welding the edge channel steel and the longitudinal main beam I-beam according to the present invention;

[0024] Figure 4 This is a schematic diagram of welding the edge channel steel and the transverse main beam I-beam according to the present invention;

[0025] Figure 5 It is a schematic diagram of the positions of the connecting plate and the I-beam of the main beam of the present invention;

[0026] Figure 6 This is a schematic diagram of the connection of the cantilever section channel steel, prefabricated support, and connecting plate of the present invention;

[0027] Figure 7 This is a schematic diagram of welding the distribution beam and the connecting plate of the present invention;

[0028] Figure 8 This is a schematic diagram of the completion of the construction platform of the present invention;

[0029] In the figure: 1- shear wall connecting plate, 2- anchor point, 3- longitudinal main beam I-beam, 4- transverse main beam I-beam, 5- edge channel steel, 6- parapet, 7- main beam cantilever section connecting plate, 8- prefabricated seamless steel pipe support, 9- distribution beam, 10- distribution beam connecting plate. DETAILED DESCRIPTION

[0030] The present invention relates to a construction method for dismantling an externally cantilevered structure of a high-rise building roof. The method is based on setting up an independent cantilevered platform, establishing a safe construction platform and facade safety protection, and realizing non-destructive cutting and dismantling.

[0031] According to the selected I-beam specifications, holes are pre-drilled in the roof parapet 6, and the horizontal and vertical main beam connecting plates and distribution beam connecting plates 10 are prefabricated. Figure 1 and Figure 2 The figure shows the front view and side view of the connection between the I-beam and the shear wall according to the present invention.

[0032] The installation of the cantilever platform follows a certain sequence: first install the longitudinal steel beams, then install the transverse steel beams, and then install the four edge channels 5 and the distribution beams 9 of the cantilever section. After all the floor steel beams are installed and welded, lay the patterned steel plates of the cantilever section.

[0033] The longitudinal main beam I-beam 3 and the transverse main beam I-beam 4 pass through the reserved holes of the parapet 6 and are fixed to the shear wall through the shear wall connecting plate 1 and chemical bolts. The steel anchor plate reserves 6 anchor points 2 which are circumferentially welded to the end side of the I-beam and are fixed to the shear wall and the I-beam through chemical bolt anchoring.

[0034] The cantilevered section is cantilevered outdoors, with each two cantilevered sections in a group. Before pushing outward from the opening, a traction rope is tied to the end, and one end of the anti-fall safety net is hung at the same time. When pushing outward, the traction rope and the safety net are released simultaneously. After being cantilevered in place, the safety net is tightened to form a safety protection. After the section inside the building is fixed and installed, the platform beams can be installed.

[0035] The longitudinal and transverse I-beams are arranged on two elevation surfaces, with all longitudinal main beam I-beams 3 on the lower layer and all transverse main beam I-beams 4 on the upper layer. The intersections of the longitudinal and transverse I-beams are connected and fixed by U-shaped clamps with a diameter of 16 mm to connect the cantilever structure platform into a whole, thereby increasing the stability of the platform and reducing the possibility of slippage.

[0036] After the main beam passes the acceptance, the adjacent channel steel 5 is connected with the cantilever section distribution beam 9. The adjacent channel steel 5 and the distribution beam 9 are installed manually by a car crane. The cantilever section crossbeam is connected with the longitudinal main beam I-beam 3 and the transverse main beam I-beam 4 through the main beam cantilever section connecting plate 7. The main beam cantilever section connecting plate 7 is fixed to the cantilever section of the steel beam by welding at intervals of 0.4 meters. The distribution beam connecting plate 10 is fixed to the two ends of the distribution beam 9 by welding, and the cantilever section distribution beam 9 is connected to the main beam by bolts. Figure 3 and Figure 4 As shown, it is a schematic diagram of welding the edge channel steel 5 and the longitudinal main beam I-beam 3 and the transverse main beam I-beam 4 according to the present invention.

[0037] First, place the 3m×0.25m stamped steel plate horizontally on the cantilever beam that has been cantilevered and fixed. When placing the stamped steel plate outside, tie the stamped steel plate with a hemp rope to prevent it from sliding and falling. The worker then stands on the stamped steel plate and fixes the stamped steel plate on the steel beam with a wire. After increasing the working surface, install the edge channel steel 5, and exchange and move the stamped steel plates in turn to complete the installation of the edge channel steel 5, the cantilever section distribution beam 9 and the patterned steel plate. Figure 5 As shown, it is a schematic diagram of the connection between the connecting plate and the main beam I-beam of the present invention.

[0038] Use the distribution beam connecting plate 10 to connect the distribution beam 9 with the main beam and fully cover the patterned steel plate. Use self-tapping screws to fix the patterned steel plate and the crossbeam into one, which is convenient for removal and transfer after completion. Figure 6 and Figure 7 As shown, it is a schematic diagram of the connection relationship between the cantilever section distribution beam 9, the prefabricated seamless steel pipe support 8, and the distribution beam connecting plate 10 of the present invention.

[0039] Insert the vertical columns of the facade protection into the prefabricated seamless steel pipe support 8 and fix them. Three horizontal cross bars are set in the middle. The wall rods are connected and fixed with the original structural column clamps. The layout of the third horizontal cross bar is determined according to the height of the demolished structure and shall not be lower than the demolished structure. The waist bars are set according to the actual erection height. After the horizontal bars and waist bars are erected, a layer of steel plate dense mesh is set inside the erected facade protection frame.

[0040] A support frame is built under the cantilevered structure to prevent the cantilevered construction platform from being hit when the cantilevered structure is cut, and to prevent the flower rack beam from being clamped by the hydraulic wire saw chain during cutting, thus affecting work efficiency.

[0041] The support frame uses three rows of steel pipe fasteners to build support frames. Longitudinal horizontal bars and transverse horizontal bars are arranged in the vertical direction of the cantilevered structure. Vertical and horizontal sweeping bars are set 0.2m away from the construction platform surface. Three layers of horizontal bars are set. The third layer of horizontal bars supports the cantilevered structure to be demolished, and the height is set according to the demolished structure.

[0042] In order to prevent concrete blocks from accidentally falling off during the demolition process and injuring people and property, anti-falling measures must be formulated before demolition to ensure safe demolition. A layer of carbon fiber cloth must be pasted on the structure in advance before demolition to prevent weathered concrete fragments from falling off during cutting and hoisting. Demolition can only begin after the carbon fiber cloth reinforcement measures are completed.

[0043] After the wire rope and concrete block of the truck crane are stable, the hook wire rope needs to be tightened before cutting. After cutting, it is hoisted to the ground by a crane. During the cutting process, the mass of the concrete block cut each time shall not exceed 500kg, and the main beam must be weighted during cutting.

[0044] When the construction environment does not meet the conditions for using a truck crane, a small cantilever crane is installed on the steel structure construction platform. The crane is equipped with a counterweight to ensure stability. After the steel wire rope of the cantilever crane and the concrete block are stable, the hook wire rope needs to be tightened before cutting. After cutting, the crane is used to lift and transport it to the roof platform, and then transport it to the ground after being broken. During the cutting process, the weight of each concrete block cut shall not exceed 500kg, and the crane must be weighted during cutting. Figure 8 As shown, it is a schematic diagram of the completion of the construction platform of the present invention.

[0045] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A construction method for dismantling the cantilevered roof structure of a high-rise building, characterized in that: The construction method includes the following construction steps: S1: hoist the prefabricated I-beams and steel pipes to the roof, drill holes in the roof parapet (6) and provide ground protection; S2: Use prefabricated main beams to build the main structure of the cantilever platform. Prefabricated I-beams are formed into a cantilever structure through the reserved holes of the parapet (6). The main beams in the longitudinal and transverse directions are arranged in two elevation planes. All longitudinal main beam I-beams (3) are on the lower layer, and all transverse main beam I-beams (4) are on the upper layer. The intersection of the longitudinal and transverse I-beams is connected and fixed by a U-shaped clamp with a diameter of 16 mm, so that the longitudinal main beam I-beam (3) and the transverse main beam I-beam (4) cantilever structure platform are connected as a whole, and the I-beams are anchored to the roof shear wall to improve the stability of the overall platform, and the welding of the transverse beams and the longitudinal beams is completed; S3: After the main beam passes the acceptance, the adjacent channel steel (5) is connected to the cantilever section distribution beam (9). The adjacent channel steel (5) and the distribution beam (9) are installed manually by a truck crane. The cantilever section cross beam is connected to the I-beam through the main beam cantilever section connection plate (7). The main beam cantilever section connection plate (7) is fixed to the cantilever section of the steel beam by welding at intervals of 0.4 meters. The distribution beam connection plate (10) is fixed to both ends of the distribution beam (9) by welding. The cantilever section distribution beam (9) is connected to the main beam by bolts. S4: First, a 3m×0.25m stamped steel plate is horizontally placed on the cantilever beam that has been cantilevered and fixed. A worker then stands on the stamped steel plate and fixes the stamped steel plate on the steel beam with wire. After increasing the working surface, the adjacent channel steel (5) is installed. The stamped steel plates are exchanged and moved in sequence to complete the installation of the adjacent channel steel (5), the cantilever section distribution beam (9) and the patterned steel plate. S5: Use the distribution beam connecting plate (10) to connect the distribution beam (9) to the main beam and fully cover it with a patterned steel plate. Use self-tapping screws to fix the patterned steel plate and the cross beam into one piece, so as to facilitate dismantling and transfer after completion; S6: Insert the vertical columns of the facade protection into the prefabricated seamless steel pipe support (8) and fix them. Three horizontal cross bars are arranged in the middle. The wall connecting rods are connected and fixed with the original structural column clamps. The layout of the third horizontal cross bar is determined according to the height of the demolished structure and shall not be lower than the demolished structure. The waist bars are arranged according to the actual erection height. After the horizontal bars and waist bars are erected, a layer of steel plate mesh is arranged inside the erected facade protection frame. S7: Use the wire rope of the truck crane to stabilize the demolished concrete block. After the hook wire rope is tightened, use a rope saw to cut it. During the cutting process, the mass of the concrete block cut each time shall not exceed 500kg.

2. A method for dismantling a high-rise building roof cantilever structure according to claim 1, characterized in that: The prefabricated main beam in step S2 is customized according to the roof size of the high-rise building and the length of the cantilever structure. The length of the cantilever section needs to be 0.5m longer than the length of the cantilever structure, and the height of the vertical pole in the facade protection system is 0.5m higher than the height of the cantilever structure.

3. A method for dismantling a high-rise building roof cantilever structure according to claim 1, characterized in that: In step S2, the prefabricated main beam is fixed to the shear wall through the shear wall connection plate (1) of the power distribution room and chemical bolts. The shear wall connection plate (1) has six reserved anchor points (2) which are circumferentially welded to the end side of the I-beam, and the shear wall and the I-beam are fixed together by chemical bolt anchoring.

4. A method for dismantling a high-rise building roof cantilever structure according to claim 1, characterized in that: Before cutting the concrete block in step S7, carbon fiber cloth is used for reinforcement. The carbon fiber cloth is arranged throughout the entire length and the overlap length is not less than 100 mm. The thickness of the base glue does not exceed 0.4 mm. After the carbon fiber cloth is pasted, the curing time shall not be less than 3 days.

5. A method for dismantling a high-rise building roof cantilever structure according to claim 1, characterized in that: In step S7, when the construction environment does not meet the conditions for using a truck crane, a small cantilever crane is installed on the steel structure construction platform, and a counterweight is set on the crane to ensure stability. After the steel wire rope of the cantilever crane and the concrete block are stable, the hook wire rope needs to be tightened before cutting. After cutting, the concrete block is hoisted to the roof platform by a crane and transported to the ground after being crushed. During the cutting process, the mass of the concrete block cut each time shall not exceed 500kg, and the crane must be weighted during cutting.

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