A construction method for cantilever roof structure

Abstract

The invention discloses a construction method for a roof cantilever structure, which can improve the safety and construction quality of the cantilever structure construction; the construction method comprises: pre-embedded sleeves; when the main structure construction of the frame layer is completed and the concrete strength of the N-1th layer is not less than 20MPa, removing part of the climbing frame protection mesh at the N-1th layer; using the climbing frame as an operating platform, and installing the cantilever main beam in the circumferential direction of the outer periphery of the N-1th layer; removing the climbing frame from the N-1th layer to the frame layer, and when the concrete strength of the Nth layer is not less than 20MPa, using a pull rod assembly to connect the cantilever main beam and the Nth layer; setting up a cantilever support frame on the cantilever main beam, connecting the cantilever support frame, an interlayer support frame one and an interlayer support frame two into an integral structure, and extending the cantilever support frame upward to a preset position of the frame layer; setting up a template of the cantilever structure at a preset position on the top of the cantilever support frame, and pouring concrete in the space surrounded by the template to form the cantilever structure, and the like.

Description

Technical Field

[0001] The invention relates to the technical field of building engineering, and in particular to a construction method of a roof cantilever structure. Background Art

[0002] House buildings usually have a frame layer on the roof. The frame layer is generally a concrete frame structure, and there is a cantilever structure cantilevering out of the roof. Since the construction of the cantilever structure is done in the air, there are safety risks during the construction process. The construction of the cantilever structure usually uses scaffolding as the formwork support. Since the cantilever structure is constructed in the air, it is difficult to set up the scaffolding, and its stability will also be affected. Moreover, during the scaffolding operation, it will also bear the pressure from the formwork and the concrete of the cantilever structure. Insufficient anti-overturning performance of the scaffolding will seriously affect the construction of the cantilever structure and cause safety accidents. Therefore, how to set up the formwork support structure of the cantilever structure, design the construction process of the cantilever structure, and ensure the safety and construction quality of the cantilever structure are the key issues to be considered during the construction of the cantilever structure. Summary of the invention

[0003] At least one of the purposes of the present invention is to provide a construction method for a roof cantilever structure in order to overcome the problems existing in the above-mentioned prior art. During the construction of the roof cantilever structure, a cantilever support frame can be set up to provide stable support for the construction of the cantilever structure in the air, thereby ensuring the safety and construction quality of the cantilever structure construction.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention includes the following aspects.

[0005] A construction method for a roof cantilever structure, comprising: Step 1: When the floor construction reaches the N-1th floor, pre-embed the casing at the preset position of the side beam or wall of the floor; when the floor construction reaches the Nth floor, pre-embed the casing or casing group at the preset position of the side beam or wall of the floor; Step 2: When the main structure of the frame layer is completed and the concrete strength of the N-1 layer is not less than 20MPa, remove part of the climbing frame protection mesh at the N-1 layer; Step 3: Use the climbing frame as an operating platform and install the cantilevered main beam around the outer periphery of the N-1 layer; Step 4: Remove the climbing frame from the N-1th floor to the frame layer. When the concrete strength of the Nth floor is not less than 20MPa, use a tie rod assembly to connect the cantilever main beam and the Nth floor. Step 5: Set up a cantilever support frame on the cantilever main beam, connect the cantilever support frame, the interlayer support frame 1 and the interlayer support frame 2 into an integral structure, and extend the cantilever support frame upward to a preset position of the structure layer; Step 6: Set up a template of the cantilever structure at a preset position on the top of the cantilever support frame; Step 7: Pour concrete in the space enclosed by the formwork to form a cantilever structure.

[0006] Preferably, in step three, during the installation of the cantilever main beam, high-strength bolts are inserted into the sleeves of the N-1th layer, and the three bolt holes arranged in isosceles triangles on the connecting steel plate are passed through the corresponding high-strength bolts, so that the outer end of the cantilever main beam is tilted upward by 2 cm, and then steel washers and double nuts are respectively inserted into the two ends of the high-strength bolts to install the cantilever main beam at the preset position of the N-1th layer.

[0007] Preferably, in step four, when installing the tie rod assembly, install a cotter pin into the N-layer pre-buried sleeve, connect the pull ring of the second tie rod and the cotter pin of the N-layer, screw the nut assembly into the second tie rod from the thread head of the second tie rod until the nut assembly is rotated to the extreme position of the thread head, and after the first tie rod is screwed into the nut assembly through the thread head, adjust the nut assembly until the pull ring of the first tie rod is aligned with the lifting ear on the cantilever main beam, and connect the pull ring and the lifting ear of the first tie rod.

[0008] Preferably, when the length of the pull rod assembly is less than the preset length requirement, a connecting plate is used as a lengthening structure, and the pull ring of the first pull rod is replaced with a sheet structure. The thickness of the sheet structure is equal to the diameter of the first pull rod, and the sheet structure is integrally formed with the first pull rod, and the connecting plate is integrally formed or welded with the sheet structure of the first pull rod; after the first pull rod is screwed into the nut assembly through the thread head, the nut assembly is adjusted until the connecting plate connected to the first pull rod is aligned with the lifting ear on the cantilever main beam, and the connecting plate and the lifting ear are connected.

[0009] Preferably, the lengths of the first and second tie rods extending into the nut assembly are not less than 60 mm; the interlayer spacing between the N-1 layer and the N layer is 3.1 m, and the interlayer spacing between the N layer and the frame layer is 4.3 m.

[0010] Preferably, in step five, before erecting the cantilever support frame, the installation position of each row of vertical poles on the cantilever main beam is determined according to the number of vertical pole rows of the cantilever support frame and the spacing between adjacent rows of vertical poles, and then adjustable positioning piles are installed at the determined installation positions.

[0011] Preferably, the adjustable positioning pile includes an adjustable base and a positioning pile, the adjustable base includes a horizontal part, a bending part and an adjusting part, one end of the horizontal part is integrally connected to the bending part, the other end of the horizontal part is hinged to the adjusting part, a connecting hole is provided on the adjusting part, and the positioning pile is vertically arranged on the top of the horizontal part and fixedly connected to the horizontal part.

[0012] Preferably, the cantilever main beam is made of I-beam, and one or more positioning bolts are vertically arranged at the bottom of the upper flange plate of the cantilever main beam. The positioning bolts are located on one side of the web of the cantilever main beam, and the adjustment part is connected to the positioning bolts through a nut.

[0013] Preferably, the installation process of the adjustable positioning pile includes: rotating the adjusting part so that the horizontal part and the bent part engage the flange plate at the top of the cantilevered main beam, rotating the adjusting part so that the connecting hole of the adjusting part passes through the positioning bolt at the bottom of the flange plate, and then screwing the nut into the positioning bolt to clamp the adjusting part and the flange plate.

[0014] Preferably, in step six, the formwork of the cantilever structure includes a first cantilever beam formwork and a second cantilever beam formwork, and the first cantilever beam formwork and the second cantilever beam formwork both include a beam bottom formwork and a beam side formwork. Before installing the formwork of the cantilever structure, an adjustable top support is installed on the top of the column from the third row to the edge of the N-1 layer, and after adjusting the height of each adjustable top support respectively, the beam bottom formwork support one is installed on the adjustable top support corresponding to the first cantilever beam, and the beam bottom formwork support two is installed on the adjustable top support corresponding to the second cantilever beam, and then the beam bottom formwork and beam side formwork of the first cantilever beam are installed on the beam bottom formwork support one, and the beam bottom formwork and beam side formwork of the second cantilever beam are arranged on the beam bottom formwork support two, and the beam bottom formwork of the first cantilever beam and the beam side formwork of the second cantilever beam are connected, and the beam side formwork of the first cantilever beam and the beam side formwork of the second cantilever beam are connected.

[0015] In summary, due to the adoption of the above technical solution, the present invention has at least the following beneficial effects: By arranging a cantilever main beam on the N-1 floor, the cantilever main beam is connected to the N floor through a tie rod assembly, which can provide effective support for the erection of the cantilever support frame and the construction of the cantilever structure of the frame layer. By erecting the cantilever support frame on the cantilever main beam, the cantilever support frame, the interlayer support frame one, and the interlayer support frame two are connected into an integral structure, which improves the stability of the cantilever support frame. When the cantilever structure of the frame layer is subsequently constructed using the cantilever support frame, the construction safety of the frame layer can be guaranteed.

[0016] By arranging adjustable positioning piles on the cantilever main beam, the uprights of the cantilever support frame can be prevented from slipping relative to the cantilever main beam, thereby further ensuring the stability of the cantilever support frame; the adjustable positioning piles can be detachably arranged at any position in the length direction of the cantilever main beam, and can be stably connected to the positioning bolts on the cantilever main beam, and can also effectively prevent the positioning piles from slipping under the action of external force; the installation of the adjustable positioning piles and the cantilever main beam avoids the drilling operation on the cantilever main beam, which is beneficial to maintaining the integrity of the cantilever main beam structure, improving the supporting effect of the cantilever main beam, and is also beneficial to the turnover use of the cantilever main beam; using the climbing frame on the outside of the floor as an operating platform for the installation of the cantilever main beam eliminates the support and erection work of the cantilever main beam, which is beneficial to ensuring the safety of the installation of the cantilever main beam, reducing the difficulty of installing the cantilever main beam, and improving the installation efficiency.

[0017] When the length of the tie rod assembly is less than the preset length, a connecting plate is provided as a lengthening structure so that the tie rod assembly connects the cantilever main beam and the N layer, which can effectively tie the cantilever main beam and improve the safety of the cantilever support frame and the cantilever main beam construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a roof cantilever structure formwork support system according to an exemplary embodiment of the present invention.

[0019] Figure 2 It is a structural schematic diagram of a roof cantilever structure formwork support system according to another exemplary embodiment of the present invention.

[0020] Figure 3 It is a schematic diagram of the connection between the adjustable positioning piles and the cantilevered main beam according to an exemplary embodiment of the present invention.

[0021] Figure 4 It is a schematic diagram of the cantilever main beam of an exemplary embodiment of the present invention from another perspective.

[0022] Figure 5 It is a schematic diagram of the connection between the cantilevered main beam and the N-1 layer of an exemplary embodiment of the present invention.

[0023] Figure 6 It is a schematic diagram of the connection between the cantilevered main beam and the connecting beam of an exemplary embodiment of the present invention.

[0024] Figure 7 It is a schematic structural diagram of a tie rod assembly according to an exemplary embodiment of the present invention.

[0025] Figure 8 yes Figure 7 Cross-sectional view of the tie rod assembly 2-2.

[0026] Fig. 9 Schematic diagram of the first pull rod structure.

[0027] Fig.10 It is a schematic diagram of the connection structure between the first tie rod and the cantilevered main beam of an exemplary embodiment of the present invention.

[0028] Fig.11 Schematic diagram of the second tie rod and N-layer connection structure of an exemplary embodiment of the present invention.

[0029] Fig.12 Schematic diagram of another connection structure between the second tie rod and the N layers according to an exemplary embodiment of the present invention.

[0030] Fig.13 It is a construction flow chart of a roof cantilever structure according to an exemplary embodiment of the present invention.

[0031] Fig.14 It is a schematic diagram of the connection structure between the first tie rod and the cantilevered main beam of another exemplary embodiment of the present invention.

[0032] Fig.15 2 is another structural schematic diagram of the first pull rod.

[0033] Markings in the figure: 1-cantilever main beam, 101-connecting steel plate, 102-positioning bolt, 103-lifting ear, 104-pin, 105-pin anti-drop buckle, 2-cantilever support frame, 201-vertical pole, 202-horizontal pole, 203-adjustable top support, 204-safety net; 205-hard protection, 206-reinforcement rod, 207-horizontal scissors brace, 208-vertical scissors brace, 209-diagonal brace, 3-interlayer support frame one, 4-interlayer support frame two, 5-pull rod assembly, 501-first pull rod, 502-second pull rod, 503-nut assembly, 5031-adjusting nut, 5032-connecting rib, 6-adjustable positioning pile, 601-adjustable base, 602-positioning pile, 6011-horizontal part, 6012-bending part, 6013-adjusting part, 7-N-1 layer, 8- N layer, 9-frame layer, 10-cantilever structure, 11-edge protection rod, 12-operating platform, 13-dense mesh safety net, 14-connecting beam, 15-split pin, 16-sleeve, 17-connecting plate. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments to make the purpose, technical solutions and advantages of the present invention more clearly understood. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0035] refer to Figure 1 The roof cantilever structure formwork support system of an exemplary embodiment of the present invention includes a cantilever main beam 1, a cantilever support frame 2, an interlayer support frame 1 3, an interlayer support frame 2 4 and a tie rod assembly 5, wherein the cantilever main beam 1 is arranged on the side beam or wall of the N-1 layer 7 (the N layer represents the roof layer, and the N-1 layer represents the next layer of the roof layer), the cantilever support frame 2 is arranged on the cantilever main beam 1 and extends upward to the frame layer 9, the interlayer support frame 1 3 is arranged between the N-1 layer 7 and the N layer 8, the interlayer support frame 2 4 is arranged between the N layer 8 and the frame layer 9, the cantilever support frame 2 is connected to the interlayer support frame 1 3, and the cantilever support frame 2 is also connected to the interlayer support frame 2 4, and the tie rod assembly 5 is used to connect the cantilever main beam 1 and the N layer 8.

[0036] The cantilever main beam 1 and the pull rod assembly 5 can provide stable support for the cantilever support frame 2 to ensure the stability of the cantilever support frame 2. After the interlayer support frame 1 3, the interlayer support frame 2 4 and the cantilever support frame 2 are connected into an integral structure, the stability of the cantilever support frame 2 can be further guaranteed. During the subsequent construction of the formwork of the cantilever structure 10 and the cantilever structure 10, the safety of high-altitude operations is effectively guaranteed.

[0037] The cantilever main beam 1 is made of I-beam, and one end of the cantilever main beam 1 is provided with a connecting steel plate 101 (using Q235 steel plate). The cantilever main beam 1 is connected to the outer wall of the N-1 floor 7 through the connecting steel plate 101 and high-strength bolts (reference Figure 1 , Figure 4 , Figure 5 ), the cantilever main beams 1 are evenly arranged along the circumference of the outer wall of the N-1 floor 7; at the positive corner of the N-1 floor 7, the cantilever main beams 1 are inclined, and the adjacent cantilever main beams 1 are connected by a connecting beam 14 (using 16# I-beam), refer to Figure 6 The connecting beam 14 is connected to the cantilever main beam 1 through a U-shaped clamp. The length of the cantilever main beam 1 is 1.5m~2.9m (the specific length is determined according to the cantilever length of the cantilever structure). The top of the cantilever main beam 1 is provided with one or more lifting ears 103 for connecting the tie rod assembly 5. The distance between the lifting ear 103 and the end of the cantilever main beam 1 and the distance between adjacent lifting ears 103 are determined according to the length of the cantilever main beam 1. The angle between the tie rod assembly 5 and the cantilever main beam 1 is 45~60 degrees.

[0038] One or more adjustable positioning piles 6 are provided on the cantilever main beam 1. The adjustable positioning piles 6 are used to locate the position of the vertical pole 201 of the cantilever support frame 2 and prevent the vertical pole 201 from slipping, thereby ensuring the stability and safety of the cantilever support frame 2. The number of adjustable positioning piles 6 is determined according to the number of vertical poles 201 of the cantilever support frame 2. Figure 1 , Figure 3The adjustable positioning pile 6 includes an adjustable base 601 and a positioning pile 602. The adjustable base 601 includes a horizontal portion 6011, a bending portion 6012 and an adjusting portion 6013. One end of the horizontal portion 6011 is integrally connected to the bending portion 6012, and the other end of the horizontal portion 6011 is hinged to the adjusting portion 6013 (such as by a hinge connection). The adjusting portion 6013 is provided with a connecting hole. The positioning pile 602 is vertically arranged on the top of the horizontal portion 6011 and is fixedly connected to the horizontal portion 6011. One or more positioning bolts 102 are vertically arranged at the bottom of the upper flange plate of the cantilever main beam 1 (the distance between adjacent positioning bolts is determined according to the design and construction requirements). The positioning bolts 102 are arranged on the flange plate on one side of the web. The positioning bolts 102 The top is welded to the bottom of the flange plate, and the adjusting part 6013 is connected to the positioning bolt 102 through a nut; when installing the adjustable positioning pile 6 on the cantilever main beam 1, the flange plate at the top of the cantilever main beam 1 is inserted between the horizontal part 6011 and the bent part 6012, and the adjusting part 6013 is rotated to make the connection hole on the adjusting part 6013 pass through the positioning bolt 102, and the nut is inserted into the positioning bolt 102 to fix the cantilever main beam 1 and the adjusting part 6013 together to complete the connection between the adjustable positioning pile 6 and the cantilever main beam 1. When the position of the adjustable positioning pile 6 needs to be adjusted, the nut is removed, and the adjusting part 6013 is screwed out of the positioning bolt 102, so that the adjustable positioning pile 6 can slide along the cantilever main beam 1 to adjust the position of the adjustable positioning pile 6. The horizontal part 6011, the bent part 6012 and the adjusting part 6013 can all be made of steel plates, and the bent part 6012 is formed by bending one end of the horizontal part 6011.

[0039] The cantilever support frame 2 includes multiple rows of uprights 201 (at least three rows, the specific number of rows is determined according to the length of the cantilever structure 10) arranged along the length direction of the cantilever main beam 1. Figure 2 More rows of vertical poles are shown for longer cantilever structure construction). The bottom of each row of vertical poles 201 is connected to the corresponding adjustable positioning piles 6 on the cantilever main beam 1 to ensure the accurate row spacing of the vertical poles 201 and prevent the vertical poles 201 from slipping, thereby ensuring the stability of the cantilever support frame 2. Each row of vertical poles 201 extends to the frame layer 9 in the height direction. Multiple rows of vertical poles 201 are connected by horizontal poles 202 (including transverse horizontal poles and longitudinal horizontal poles). Multiple rows of horizontal poles 202 are arranged along the height direction of the vertical poles 201, and the distance between adjacent rows of horizontal poles 202 is 1. 3~1.5m, adjust the distance between the horizontal rod 202 and the top or bottom of the vertical rod 201 near the top or bottom of the vertical rod 201; when the horizontal rod 202 is located between the N-1 layer 7 and the N layer 8, each row of horizontal rods 202 is extended from the vertical rod 201 to the interlayer support frame 3, and is connected to the cross bar of the interlayer support frame 3 to form an integral structure; when the horizontal rod 202 is located between the N layer 8 and the frame layer 9, each row of horizontal rods 202 is extended from the vertical rod 201 to the interlayer support frame 2 4, and is connected to the cross bar of the interlayer support frame 2 4 to form an integral structure.

[0040] The top of the first row of vertical poles 201 from the outside to the inside of the cantilever support frame 2 is provided with an edge protection rod 11, and the edge protection rod 11 is connected with a dense safety net 13. The top of the first row of vertical poles 201 and the second row of vertical poles 201 is provided with an operating platform 12 (which can be fully covered with steel mesh or platform board), and the top of the vertical poles 201 from the third row to the edge of the N-1 layer 7 are all provided with adjustable top supports 203 for supporting the template of the cantilever structure 10. A safety net 204 is also provided between the second row of vertical poles 201 and the third row of vertical poles 201 at the top of the cantilever support frame 2 to ensure the safety of the cantilever structure 10 construction of the frame layer 9.

[0041] The cantilever structure 10 is 0.4~2m long. The cantilever structure 10 includes a first cantilever beam and a second cantilever beam which are perpendicular to each other. One end of the first cantilever beam is connected to the crossbeam of the frame layer 9, and the other end is connected to the second cantilever beam; the third row of vertical poles 201 near the top of the cantilever support frame 2 is connected to the adjacent row of vertical poles 201 through a reinforcing rod 206 to further improve the stability of the support for the second cantilever beam and the bottom formwork; between the N-1 layer 7 and the N layer 8, the vertical poles 201 of the cantilever support frame 2 near the N-1 layer 7 and the vertical poles of the interlayer support frame 3 are connected through a reinforcing rod 206 to further improve the stability of the connection between the cantilever support frame 2 and the interlayer support frame 3, thereby improving the overall stability of the cantilever support frame 2.

[0042] The cantilever support frame 2 is fully paved with wooden beams near the bottom, and a formwork is laid on the top of the wooden beams. The formwork extends from the cantilever support frame 2 to the 7th floor of the N-1 layer. The wooden beams and the formwork serve as hard protection 206 to improve the stability of the cantilever support frame 2 and prevent objects from falling, thereby ensuring construction safety. A plurality of horizontal scissors braces 207 are provided in the height direction of the cantilever support frame 2, and the horizontal scissors braces 207 are respectively arranged near the N-1 layer 7, the N layer 8 and the frame layer 9, and the horizontal scissors braces 207 respectively connect the cantilever support frame 2 and the interlayer support frame 1 3, and the cantilever support frame 2 and the interlayer support frame 2 4; between the N-1 layer 7 and the N layer 8, the cantilever support frame 2 is also provided with a diagonal brace 209, and between the N layer 8 and the frame layer 9, the cantilever support frame 2 is also provided with a vertical scissors brace 208, and the vertical scissors brace 208 connects the cantilever support frame 2 and the interlayer support frame 2 4, so as to improve the overall stability of the cantilever support frame 2 and ensure the construction safety of the cantilever structure 10 of the formwork and the frame layer 9.

[0043] refer to Figure 7-Figure 9The tie rod assembly 5 includes a first tie rod 501, a second tie rod 502 and a nut assembly 503. A pull ring is provided at one end of the first tie rod 501, and a thread head (length 350-400 mm) is provided at the other end. Similarly, a pull ring is provided at one end of the second tie rod 502, and a thread head (length 350-400 mm) is provided at the other end. The nut assembly 503 includes two mutually parallel adjusting nuts 5031, and the two adjusting nuts 5031 are connected by a connecting rib 5032. A plurality of connecting ribs 5032 are evenly arranged along the circumference of the adjusting nuts 5031, and the two ends of the connecting rib 5032 are respectively welded to the adjusting nuts 5031; the first tie rod 501 is connected to an adjusting nut 5031 of the nut assembly 503 through a thread head, and the second tie rod 502 is connected to another adjusting nut 5031 of the nut assembly 503 through a thread head; the first tie rod 501 is connected to the lifting ear 103 of the cantilevered main beam 1 through a pull ring (reference Fig.10 ), the second tie rod 502 is connected to the N layer 8 through a pull ring, and a split pin 15 is detachably provided on the side beam or wall of the N layer 8, and the split pin 15 is detachably connected to the second tie rod 502 (refer to Fig.11 , Fig.12 ).

[0044] The present invention also provides a construction method for a roof cantilever structure, which adopts the above-mentioned roof cantilever structure template support system for construction. Fig.13 , the construction method comprises the following steps: Step 1: When the floor construction reaches the N-1th floor 7, a sleeve 16 (preferably a PVC threaded sleeve with a diameter of 25 mm) is embedded at the preset position of the side beam or wall of the floor. The sleeve 16 of the floor passes through the side beam or wall, and the distance between the center line of the sleeve 16 and the top surface of the N-1 floor 7 is 250~300mm; when the construction reaches the Nth floor 8, a sleeve 16 or a sleeve group (including two sleeves) is embedded at the preset position of the side beam or wall of the floor, and the distance between the center line of the sleeve 16 and the top surface of the Nth floor 8 is 150~250mm The sleeve 16 deviates laterally from the vertical pole of the cantilever support frame 2 by 50~100mm. This layer of sleeve 16 can penetrate the side beam or wall, or be in the side beam or wall. When in the side beam or wall, the length of the sleeve 16 extending into the side beam or wall is 150~180mm. The diameter of one end of the sleeve 16 located in the side beam or wall is larger than the diameter of the other end to prevent the sleeve 16 from withdrawing from the side beam or wall; when the sleeve group is pre-buried, the lateral distance between the two sleeves 16 of the sleeve group is 100~120mm. Before the sleeve 16 is embedded, a horizontal line is set at the preset position of the corresponding layer side beam or wall to embed the sleeve 16 at a uniform height, and the end of the sleeve 16 is sealed to prevent concrete or other debris from entering the sleeve 16. During the embedding of the sleeve 16, the sleeve 16 and the steel bars in the side beam or wall are firmly tied according to the preset embedding position of the sleeve 16 to prevent the sleeve 16 from shifting during the concrete vibration process. During the implementation process, one of the interlayer spacings between the N-1 layer 7 and the N layer 8 is 3.1m, and one of the interlayer spacings between the N layer 8 and the frame layer 9 is 4.3m.

[0045] Step 2: When the main structure construction of the frame layer 9 is completed and the concrete strength of the N-1 layer 7 (using C30 concrete) is not less than 20MPa, remove part of the climbing frame protection mesh at the N-1 layer 7.

[0046] Step 3: Use the climbing frame as an operating platform to install the cantilever main beam 1 circumferentially around the outer periphery of the N-1 layer 7; install one cantilever main beam 1 (preferably 16# I-beam) every 1~1.5m. When the length of the cantilever main beam 1 is greater than 1.8m, install two lifting ears 103 on the cantilever main beam 1. The position of each lifting ear 103 is determined according to the design position to ensure that when the tie rod assembly 5 is installed on the cantilever main beam 1, the working angle of the tie rod assembly 5 is 45~60 degrees. During the installation of the cantilever main beam 1, insert a high-strength bolt with a diameter of 20mm and a strength grade of A8.8 into the sleeve 16 of the N-1 layer 7, pass the three isosceles triangle-arranged bolt holes on the connecting steel plate 101 through the corresponding high-strength bolts, and then insert steel washers and double nuts at both ends of the high-strength bolts, and install the cantilever main beam 1 at the preset position of the N-1 layer 7; after the cantilever main beam 1 is installed, use a connecting beam 14 to connect the adjacent cantilever main beams 1 at the positive angle position. When installing the cantilever main beam 1, the outer end of the cantilever main beam 1 (the end of the cantilever main beam 1 opposite to the connecting steel plate 101) is tilted upward by 2 cm. After the cantilever support frame 2 is installed, the outer end of the cantilever main beam 1 can be prevented from sagging.

[0047] Step 4. Remove the climbing frame from the N-1th layer 7 to the frame layer 9. When the strength of the concrete of the Nth layer 8 (using C30 concrete) is not less than 20MPa, use the tie rod assembly 5 to connect the cantilever main beam 1 and the Nth layer 8; the overall length of the tie rod assembly 5 is determined according to the height of the N-1 layer 7 to the N layer 8 and the length of the cantilever main beam 1, and the number of tie rod assemblies 5 is determined according to the length of the cantilever main beam 1. The first tie rod 501 and the second tie rod 502 are both made of round steel (HB300) with a diameter of 20mm, the adjusting nut 5031 is made of 45# steel with a size of M50, and the connecting rib 5032 is made of steel with a diameter of 14mm. After the tie rod assembly 5 is tightened, the length of the first tie rod 501 and the second tie rod 502 extending into the nut assembly 503 is not less than 60mm to ensure the stability of the tie rod assembly structure.

[0048] When installing the tie rod assembly 5, install the cotter pin 15 into the pre-buried sleeve 16 of the N layer 8, use the pin 104 and the anti-drop buckle to connect the pull ring of the second tie rod 502 and the cotter pin 15 of the N layer 8, screw the nut assembly 503 from the thread head of the second tie rod 502 into the second tie rod 502 until the nut assembly 503 is rotated to the extreme position of the thread head, after the first tie rod 501 is screwed into the nut assembly 503 through the thread head, adjust the nut assembly 503 until the pull ring of the first tie rod 501 is aligned with the ear 103 on the cantilever main beam 1, use the pin 104 and the anti-drop buckle to connect the pull ring and the ear 103 of the first tie rod 501, check the tightness of the tie rod assembly 5, and adjust the nut assembly 503 to ensure that the first tie rod 501 and the second tie rod 502 are taut and evenly stressed.

[0049] The lengths of the first tie rod 501, the second tie rod 502 and the nut assembly 503 are set according to the standard floor spacing and design requirements. In certain parts of the floor, when the length of the tie rod assembly 5 is less than the preset length requirement, a connecting piece 17 can be used as a lengthening structure to connect the first tie rod 501 and the cantilever main beam 1 through the connecting piece 17, so that the tie rod assembly 5 meets the use requirements. Fig.14 The connecting piece 17 is made of steel, and is provided with through holes near both ends. The connecting piece 17 is connected to the U-shaped lifting ear 103 at the top of the cantilever main beam 1 through a pin 104 and an anti-drop buckle. The connecting piece 17 is also welded or bolted to the first tie rod 501; when the connecting piece 17 is welded to the first tie rod 501, the pull ring of the first tie rod 501 is replaced by a sheet structure, refer to Fig.15 The thickness of the sheet structure is equal to the diameter of the first tie rod 501. The sheet structure is integrally formed with the first tie rod 501. The pull ring of the first tie rod 501 is replaced by the sheet structure. The welding of the sheet structure and the connecting plate 17 can increase the contact area of ​​the connecting part between the first tie rod 501 and the connecting plate 17, prevent the connecting part between the first tie rod 501 and the connecting plate 17 from being damaged, thereby increasing the reliability of the connection between the first tie rod 501 and the connecting plate 17, so that the tie rod assembly 5 can play an effective pulling role on the cantilever main beam 1.

[0050] Step 5: Set up a cantilever support frame 2 on the cantilever main beam 1, connect the cantilever support frame 2, interlayer support frame 1 3 and interlayer support frame 2 4 into an integral structure, and extend the cantilever support frame 2 upward to a preset position of the structure layer.

[0051] Before installing the cantilever support frame 2, the installation position of each row of vertical poles 201 on the cantilever main beam 1 is determined according to the number of rows of vertical poles 201 of the cantilever support frame 2 and the spacing between adjacent rows of vertical poles 201, and then the adjustable positioning piles 6 are installed at the determined installation positions to prevent the vertical poles 201 from slipping and ensure the stability of the cantilever support frame 2 structure. The installation process of the adjustable positioning piles 6 includes: rotating the adjustment part 6013 to make the horizontal part 6011 and the bending part 6012 engage with the flange plate at the top of the cantilever main beam 1, rotating the adjustment part 6013, Make the connecting hole of the adjustment part 6013 pass through the positioning bolt 102 at the bottom of the flange plate, and then screw the nut into the positioning bolt 102 to clamp the adjustment part 6013 and the flange plate; after the adjustable positioning pile 6 is installed, connect the vertical pole 201 of the cantilever support frame 2 and the positioning pile 602 of the adjustable positioning pile 6 (the vertical pole can be inserted into the positioning pile, or other methods can be used to connect), install the cantilever support frame 2, and connect the cantilever support frame 2 and the interlayer support frame 1 3 and the interlayer support frame 2 4 into an integral structure.

[0052] Step six, set up the formwork of the cantilever structure 10 at the preset position on the top of the cantilever support frame 2; the formwork of the cantilever structure 10 includes a first cantilever beam formwork and a second cantilever beam formwork, and the first cantilever beam formwork and the second cantilever beam formwork both include a beam bottom formwork and a beam side formwork. Before installing the formwork of the cantilever structure 10, install an adjustable top support 203 on the top of the column from the third row to the edge of the N-1 layer 7, and after adjusting the height of each adjustable top support 203 respectively, install the beam bottom formwork support one on the adjustable top support 203 corresponding to the first cantilever beam, and install the beam bottom formwork support two on the adjustable top support 203 corresponding to the second cantilever beam, and then install the beam bottom formwork and beam side formwork of the first cantilever beam on the beam bottom formwork support one, and set the beam bottom formwork and beam side formwork of the second cantilever beam on the beam bottom formwork support two, and connect the beam bottom formwork of the first cantilever beam and the beam side formwork of the second cantilever beam, and connect the beam side formwork of the first cantilever beam and the beam side formwork of the second cantilever beam. When the overall length of the cantilever structure 10 is not more than 0.6m, the beam side formwork of the first cantilever beam and the beam side formwork of the second cantilever beam are made into an integrated structure, and the beam bottom formwork of the first cantilever beam and the beam bottom formwork of the second cantilever beam are made into an integrated structure (or the beam bottom formwork of the main structure of the frame layer is used as the beam bottom formwork of the second cantilever beam). Since the length of the cantilever structure 10 is relatively short, only the second beam bottom formwork support 2 can be set, and the formwork support on the interlayer support frame 2 4 can be used as the formwork support for the first cantilever beam.

[0053] Step 7: pour concrete in the space surrounded by the formwork to form a cantilever structure 10.

[0054] In the above process, when the concrete strength of the cantilever structure 10 reaches 100% of the design strength, the formwork, the adjustable top support 203, the cantilever support frame 2 and the cantilever main beam 1 of the cantilever structure 10 are removed in sequence.

[0055] The above is only a detailed description of the specific implementation of the present invention, rather than a limitation of the present invention. Various substitutions, modifications and improvements made by those skilled in the relevant art without departing from the principle and scope of the present invention should be included in the protection scope of the present invention.

Claims

1. A construction method for a roof cantilever structure, characterized in that: include: Step 1: When the floor construction reaches the N-1th floor (7), a sleeve (16) is pre-buried at a preset position of the side beam or wall of the floor; when the floor construction reaches the Nth floor (8), a sleeve (16) or a sleeve group is pre-buried at a preset position of the side beam or wall of the floor; Step 2: When the main structure of the frame layer (9) is completed and the concrete strength of the N-1 layer (7) is not less than 20 MPa, remove part of the climbing frame protection mesh at the N-1 layer (7); Step 3: Using the climbing frame as an operating platform, a cantilevered main beam (1) is installed around the outer periphery of the N-1 layer (7); Step 4: dismantle the climbing frame from the N-1th layer (7) to the frame layer (9), and when the concrete strength of the Nth layer (8) is not less than 20 MPa, use the tie rod assembly (5) to connect the cantilever main beam (1) and the Nth layer (8); Step 5: erecting a cantilever support frame (2) on the cantilever main beam (1), connecting the cantilever support frame (2), the interlayer support frame 1 (3) and the interlayer support frame 2 (4) into an integral structure, and extending the cantilever support frame (2) upward to a preset position of the structural layer; Step 6: Setting up a template of the cantilever structure (10) at a preset position on the top of the cantilever support frame (2); Step 7: Pour concrete in the space enclosed by the formwork to form a cantilever structure (10).

2. The construction method of the roof cantilever structure according to claim 1, characterized in that: In the step 3, during the installation of the cantilever main beam (1), a high-strength bolt is inserted into the sleeve (16) of the N-1th layer (7), and the three bolt holes arranged in an isosceles triangle on the connecting steel plate (101) are passed through the corresponding high-strength bolts, so that the outer end of the cantilever main beam (1) is tilted upward by 2 cm, and then steel washers and double nuts are respectively inserted into the two ends of the high-strength bolts to install the cantilever main beam (1) at a preset position of the N-1th layer (7).

3. The construction method of the roof cantilever structure according to claim 1, characterized in that: In the step 4, when installing the tie rod assembly (5), install the cotter pin (15) into the pre-buried sleeve (16) of the N layer (8), connect the pull ring of the second tie rod (502) and the cotter pin (15) of the N layer (8), screw the nut assembly (503) into the second tie rod (502) from the thread head of the second tie rod (502) until the nut assembly (503) is rotated to the extreme position of the thread head, and after the first tie rod (501) is screwed into the nut assembly (503) through the thread head, adjust the nut assembly (503) until the pull ring of the first tie rod (501) and the lifting ear (103) on the cantilever main beam (1) are aligned, and connect the pull ring of the first tie rod (501) and the lifting ear (103).

4. The construction method of the roof cantilever structure according to claim 3, characterized in that: When the length of the tie rod assembly (5) is less than the preset length requirement, a connecting piece (17) is used as a lengthening structure, the pull ring of the first tie rod (501) is replaced by a sheet structure, the thickness of the sheet structure is equal to the diameter of the first tie rod (501), the sheet structure and the first tie rod (501) are integrally formed, and the connecting piece (17) and the sheet structure of the first tie rod (501) are integrally formed or welded; after the first tie rod (501) is screwed into the nut assembly (503) through the thread head, the nut assembly (503) is adjusted until the connecting piece (17) connected to the first tie rod (501) and the ear (103) on the cantilever main beam (1) are aligned, and the connecting piece (17) and the ear (103) are connected.

5. The construction method of the roof cantilever structure according to claim 3, characterized in that: The lengths of the first tie rod (501) and the second tie rod (502) extending into the nut assembly (503) are both not less than 60 mm; the interlayer spacing between the N-1 layer (7) and the N layer (8) is 3.1 m, and the interlayer spacing between the N layer (8) and the frame layer (9) is 4.3 m.

6. The construction method of the roof cantilever structure according to claim 1, characterized in that: In the step 5, before erecting the cantilever support frame (2), the installation position of each row of vertical poles (201) on the cantilever main beam (1) is determined according to the number of rows of vertical poles (201) of the cantilever support frame (2) and the spacing between adjacent rows of vertical poles (201), and then the adjustable positioning piles (6) are installed at the determined installation positions.

7. The construction method of the roof cantilever structure according to claim 6, characterized in that: The adjustable positioning pile (6) comprises an adjustable base (601) and a positioning pile (602); the adjustable base (601) comprises a horizontal portion (6011), a bending portion (6012) and an adjusting portion (6013); one end of the horizontal portion (6011) is integrally connected to the bending portion (6012); the other end of the horizontal portion (6011) is hinged to the adjusting portion (6013); a connecting hole is provided on the adjusting portion (6013); the positioning pile (602) is vertically arranged on the top of the horizontal portion (6011) and is fixedly connected to the horizontal portion (6011).

8. The construction method of the roof cantilever structure according to claim 7, characterized in that: The cantilever main beam (1) is made of I-steel, and one or more positioning bolts (102) are vertically arranged at the bottom of the upper flange plate of the cantilever main beam (1), the positioning bolts (102) are located on one side of the web of the cantilever main beam (1), and the adjustment portion (6013) is connected to the positioning bolts (102) via nuts.

9. The construction method of the roof cantilever structure according to claim 8, characterized in that: The installation process of the adjustable positioning pile (6) comprises: rotating the adjusting part (6013) so that the horizontal part (6011) and the bent part (6012) engage with the flange plate at the top of the cantilevered main beam (1), rotating the adjusting part (6013) so that the connecting hole of the adjusting part (6013) passes through the positioning bolt (102) at the bottom of the flange plate, and then screwing a nut into the positioning bolt (102) to clamp the adjusting part (6013) and the flange plate.

10. The construction method of the roof cantilever structure according to any one of claims 1 to 9, characterized in that: In the step six, the template of the cantilever structure (10) includes a first cantilever beam template and a second cantilever beam template, and the first cantilever beam template and the second cantilever beam template both include a beam bottom template and a beam side template. Before installing the template of the cantilever structure (10), an adjustable top support (203) is installed on the top of the column from the third row to the edge of the N-1 layer (7), and after adjusting the height of each adjustable top support (203) respectively, a beam bottom template support 1 is installed on the adjustable top support (203) corresponding to the first cantilever beam, and a beam bottom template support 2 is installed on the adjustable top support (203) corresponding to the second cantilever beam, and then the beam bottom template and beam side template of the first cantilever beam are installed on the beam bottom template support 1, and the beam bottom template and beam side template of the second cantilever beam are set on the beam bottom template support 2, and the beam bottom template of the first cantilever beam and the beam side template of the second cantilever beam are connected, and the beam side template of the first cantilever beam is connected to the beam side template of the second cantilever beam.

Images