A temporary diagonal brace reinforcement method suitable for cantilever steel frames

Abstract

The present invention discloses a temporary diagonal brace reinforcement method suitable for cantilever steel frames, which belongs to the technical field of building structure construction, and comprises the following steps: step one, hoisting and welding the fixed end main beam and the cantilever column of the reinforcement layer respectively, and hoisting multiple groups of fixed end main beams in parallel; step two, welding the end plates at the shear wall node position and the cantilever column node position respectively, and welding the two ends of the temporary diagonal brace to the end plates at the two node positions respectively; step three, constructing the multi-span parts in the same way as the above steps, welding the end plates and temporary diagonal braces of the corresponding span areas; step four, after the reinforcement layer structure is installed, installing the upper structure on the upper side of the reinforcement layer; step five, after the upper structure is installed, cutting off all the end plates of the reinforcement layer, and removing them together with the temporary diagonal brace, and the reinforcement layer is transformed from a truss system to a frame system to reach a designed forming state. The present invention can solve the problem of inconvenience in cantilever steel frame construction without temporary piers.

Description

Technical Field

[0001] The invention belongs to the technical field of building structure construction, and in particular relates to a temporary diagonal brace reinforcement method suitable for a cantilever steel frame. Background Art

[0002] Cantilever steel frame is a common high-rise building structure, and its fixed end is mostly fixedly connected to structural modules with high rigidity such as core tube shear wall. Common construction methods often use ground-mounted steel columns or concrete columns as temporary piers, which are set at the cantilever end to provide temporary support. After the construction of the fixed end is completed to form a fixed connection, the temporary piers are removed to form a cantilever. In different design scenarios, cantilever steel frames do not have the conditions for setting temporary piers due to reasons such as too high elevation and lower site occupation. Cantilever frames lack boundary constraints and require lifting equipment to maintain the stress on components for a long time, which causes inconvenience in structural construction and affects the overall construction period. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide a temporary diagonal brace reinforcement method suitable for cantilever steel frames, which aims to solve the problem of inconvenience in cantilever steel frame construction without temporary piers.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] The present invention discloses a temporary diagonal brace reinforcement method applicable to a cantilever steel frame, comprising the following steps:

[0006] Step 1: hoist the fixed-end main beam and the cantilever column of the reinforcement layer respectively and weld them, hoist multiple groups of fixed-end main beams in parallel, weld one end of the fixed-end main beam to the fixed-end bracket on the shear wall through the fixed-end weld, keep the cantilever column and the fixed-end main beam vertical, and weld the other end of the fixed-end main beam to the beam-column node bracket installed on one side of the cantilever column through the node bracket weld;

[0007] Step 2: Weld the end plates at the shear wall node position and the cantilever column node position respectively, and weld the two ends of the temporary diagonal brace to the end plates at the two node positions respectively;

[0008] Step 3: The multi-span parts are constructed in the same way as the above steps. The multi-span main beams and the cantilever columns connected thereto are hoisted. The multi-span main beams and the beam-column node brackets are welded with node bracket welds. Then, the end plates and temporary diagonal braces of the corresponding spans are welded. The multi-frame frames are connected with connecting beams to form a truss system in the reinforcement layer.

[0009] Step 4: After the reinforcement layer structure is installed, the upper structure is installed on the upper side of the reinforcement layer;

[0010] Step 5: After the superstructure is installed, cut off all the end plates of the reinforcement layer and remove them together with the temporary diagonal braces. The reinforcement layer is transformed from a truss system to a frame system to reach the designed state.

[0011] Furthermore, in step four, during the construction process, the upper cantilever columns in the non-reinforced layer are hoisted first, and the upper cantilever columns and the cantilever columns of the reinforced layer are connected by butt welds. Then the upper main beam is hoisted, and the two ends of the upper main beam are respectively welded to the reserved corbels of the upper cantilever columns or the fixed support end corbels on the shear wall, and connecting beams are used to connect multiple frames.

[0012] Furthermore, in step four, when installing the superstructure, a stress detection device is also installed on the temporary diagonal brace. The stress detection device is used to detect the internal force of the temporary diagonal brace. When the monitored internal force exceeds the safety warning value during the construction process, the construction organization is adjusted, the number of floor construction personnel and equipment is reduced, and reinforcement is carried out by adding temporary diagonal braces.

[0013] Furthermore, in step four, when installing the superstructure, a deflection detection device is installed, and the deformation deflection of multiple span main beams is detected simultaneously by the deflection detection device. When it is detected that the deflection exceeds a preset deflection threshold, additional end plates are welded at the shear wall node position and the cantilever column node position, and a first joint and a second joint are respectively installed on the two additional end plates. The first joint and the second joint are respectively threadedly connected to the two ends of the threaded outer rod, and the relative distance between the first joint and the second joint can be adjusted by rotating the threaded outer rod.

[0014] Furthermore, the deflection detection equipment includes an annular guide rail, an annular slider, a vertical guide rail, a vertical slider, a displacement drive device, a test rod, a horizontal pin shaft, a first torsion reset device, an angle sensor and a detection seat. The annular guide rail is fixedly connected to the shear wall, the annular slider is slidably installed on the annular guide rail, the vertical guide rail is fixed on the annular slider, the displacement drive device can drive the vertical slider to slide vertically on the vertical guide rail, the detection seat is installed on the vertical slider, the detection seat is installed with an angle sensor, one end of the test rod is rotatably connected to the detection seat through a horizontal pin shaft, and the first torsion reset device is simultaneously connected between the test rod and the detection seat, the other end of the test rod extends outward to form a detection end, and the horizontal pin shaft is connected to the input end of the angle sensor.

[0015] Furthermore, the detection seat is rotatably connected to the vertical slider via a vertical pin shaft, and a second torsion reset device is simultaneously connected between the detection seat and the vertical slider.

[0016] Furthermore, the annular guide rail is detachably connected to the shear wall through a base plate, and the position of the annular guide rail is adjusted to keep it horizontal. A driving wheel and a tensioning wheel are rotated simultaneously on the base plate, a belt is installed between the driving wheel and the tensioning wheel, the annular slider is fixedly connected to the belt, the driving wheel is connected to a motor, and the motor is installed on the shear wall.

[0017] The beneficial effects of the present invention are:

[0018] The present invention discloses a temporary diagonal brace reinforcement method applicable to a cantilever steel frame, which divides the cantilever steel frame into a reinforcement layer and a non-reinforcement layer. The reinforcement layer is located at the bottom of the cantilever structure, and is a truss system composed of components such as the main beam, cantilever column, and connecting beam of the original design structure, and temporary diagonal braces. The cantilever beam is welded to the main structure of the fixed support end with a reserved bracket, and the temporary diagonal brace is welded to the node of the reinforcement layer through the end plate. The floor structure above the reinforcement layer in the cantilever frame is all non-reinforced layer, and the components are completely composed of the original design structure, without additional temporary components for construction, and the construction process is carried out after the overall construction of the reinforcement layer is completed.

[0019] Compared with the prior art, the present invention has the following advantages and outstanding effects:

[0020] (1) The present invention facilitates the construction process by setting up temporary diagonal braces, avoids the process of setting up and removing temporary piers, and speeds up the construction.

[0021] (2) The construction site occupies less space, and the construction process is completed on the cantilevered working surface, reducing the conflict with the site below the construction area.

[0022] (3) The construction conditions are not limited by the height of the structure, and there is no need for ground-mounted piers to support the structure. The construction conditions can still be met even when the structure is at a high height, thus reducing the construction risks existing in the existing technology.

[0023] (4) The structural rigidity is relatively large, and reinforcement is carried out on the basis of the original structure, making full use of the structural rigidity to carry loads. At the same time, the reinforcement and dismantling process is simple, and after the dismantling process is completed, it can match the original design.

[0024] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or those skilled in the art may be taught from the practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0026] Figure 1It is a flow chart of the temporary diagonal brace reinforcement method of the present invention;

[0027] Figure 2 It is a schematic diagram of the structure of the reinforcement layer and the non-reinforcement layer;

[0028] Figure 3 It is a structural schematic diagram of a vertical guide rail;

[0029] Figure 4 for Figure 3 A magnified view at point A;

[0030] Figure 5 This is a schematic diagram of the connection between the fixed-end main beam and the cantilever column;

[0031] Figure 6 for Figure 5 main view.

[0032] The markings in the accompanying drawings are as follows: fixed-end main beam 1, cantilever column 2, fixed-end weld 3, fixed-end corbel 4, beam-column node corbel 5, node corbel weld 6, end plate 7, temporary diagonal brace 8, multi-span main beam 9, connecting beam 10, upper cantilever column 11, butt weld 12, upper main beam 13, stress detection device 14, first joint 15, second joint 16, threaded outer rod 17, annular guide rail 18, annular slider 19, vertical guide rail 20, vertical slider 21, displacement drive device 22, horizontal pin 23, first torsion reset device 24, angle sensor 25, detection seat 26, shear wall 27, vertical pin 28, second torsion reset device 29, base plate 30, driving wheel 31, tensioning wheel 32, belt 33, motor 34, test rod 35. DETAILED DESCRIPTION

[0033] like Figure 1-6 As shown, the present invention discloses a temporary diagonal bracing reinforcement method applicable to a cantilever steel frame, wherein the cantilever steel frame includes a reinforcement layer and an upper structure installed above the reinforcement layer. In this embodiment, the reinforcement layer is two layers, including a plurality of horizontally arranged fixed-end main beams 1 and multi-span main beams 9, and vertically arranged cantilever columns 2 respectively connecting the fixed-end main beams 1 and the multi-span main beams 9. The fixed-end main beams 1 or the multi-span main beams 9 are combined with the cantilever columns 2 to form a frame, and the multiple frames are connected by connecting beams 10 to form the reinforcement layer structure.

[0034] Specifically, the temporary diagonal brace reinforcement method of the present invention comprises the following steps:

[0035] Step one, respectively hoist and weld the fixed-end main beam 1 and cantilever column 2 of the reinforcement layer, wherein first reserve the fixed-end main beam 1 on the shear wall 27, and then hoist multiple groups of fixed-end main beams 1 in parallel, weld one end of the fixed-end main beam 1 to the fixed-end corbel 4 on the shear wall 27 through the fixed-end weld 3, keep the cantilever column 2 and the fixed-end main beam 1 perpendicular, and weld the other end of the fixed-end main beam 1 to the beam-column node corbel 5 installed on one side of the cantilever column 2 through the node corbel weld 6; after welding is completed, the fixed-end main beam 1 is perpendicular to the shear wall 27, and the cantilever column 2 is parallel to the shear wall 27.

[0036] Step 2, weld the end plate 7 at the node position of the shear wall 27 and the node position of the cantilever column 2 respectively. The node position of the shear wall 27 here is the position of the intersection of the shear wall 27 and the fixed end main beam 1, and the node position of the cantilever column 2 is the position where the cantilever column 2 intersects with the beam-column node corbel 5. After the end plate 7 is welded, the two ends of the temporary diagonal brace 8 are respectively welded to the end plates 7 at the two node positions; the temporary diagonal brace 8 is used to form a diagonal web member, thereby changing the force transmission path of the original structure, reducing the internal force of the original structure rods, and thus strengthening the stiffness and bearing capacity of the structure during the construction process.

[0037] Step 3: Install the multi-span frames from the normal direction of the shear wall 27 outwards in sequence, and the multi-span parts are constructed in the same way as the above steps. When installing the multi-span parts, hoist the multi-span main beam 9 and the cantilever column 2 connected thereto, weld the multi-span main beam 9 to the beam-column node corbel 5 with the node corbel weld 6, and then weld the end plate 7 and temporary diagonal brace 8 of the corresponding span area, and connect the multi-span frames with the connecting beam 10 to form a truss system in the reinforcement layer;

[0038] Step 4: After the reinforcement layer structure is installed, the upper structure is installed on the upper side of the reinforcement layer. The floor structures above the reinforcement layer in the cantilever frame are all non-reinforced layers. The components are completely composed of the original design structure, and no additional temporary construction components are added;

[0039] Step 5: After the upper structure is installed, cut off all the end plates 7 of the reinforcement layer. When dismantling, use flame cutting or plasma cutting equipment to remove the end plates 7 and remove them together with the temporary diagonal braces 8. The reinforcement layer is transformed from a truss system to a frame system, reaching the designed forming state.

[0040] In the reinforcement method disclosed in the present invention, welding is used at the beam-column nodes where the end plates 7 are connected, and the temporary diagonal bracing members 8 are connected to the end plates 7 by welding, so that they can bear stress together with the original structure, thereby reducing the overall deformation of the structure during the construction of the upper non-reinforced layer.

[0041] In some other embodiments, the temporary diagonal brace 8 can adopt a telescopic rod with adjustable telescopic length. The length can be adjusted before installation as needed to adapt to the installation needs of different main beam tolerances. This can not only increase the stability of the installation and facilitate installation, but also reduce welding deformation during welding.

[0042] In this embodiment, in step 4, during the construction process, the upper cantilever column 11 in the non-reinforced layer is first hoisted, and the upper cantilever column 11 is connected to the cantilever column 2 of the reinforced layer by a butt weld 12, and then the upper main beam 13 is hoisted, and the two ends of the upper main beam 13 are respectively welded to the reserved bracket of the upper cantilever column 11 or the fixed support end bracket 4 on the shear wall 27, and the multiple frames are connected by a connecting beam 10. In this embodiment, the upper cantilever column 11 is first installed so that the upper structure can correspond to the reinforced layer, reducing the deformation of the upper non-reinforced layer during installation, making full use of the rigidity of the cantilever column 2 itself for bearing, and reducing deformation during construction.

[0043] In this embodiment, in step 4, when installing the upper structure, a stress detection device 14 is installed on the temporary diagonal brace 8. The stress detection device 14 is used to detect the internal force of the temporary diagonal brace 8. When the internal force monitored during the construction process exceeds the safety warning value, the construction organization is adjusted to reduce the number of floor construction personnel and equipment, and reinforcement is performed by adding temporary diagonal braces 8. By adding temporary diagonal braces 8, it can be used to additionally reinforce the reinforcement layer, thereby increasing the bearing capacity of the structure.

[0044] In this embodiment, in step four, when installing the superstructure, a deflection detection device is installed at the same time, and the deformation deflection of the multi-span main beam 9 is detected by the deflection detection device at the same time. When the deflection is detected to exceed the preset deflection threshold, additional end plates 7 are welded at the node positions of the shear wall 27 and the node positions of the cantilever column 2. The first joint 15 and the second joint 16 are respectively installed on the two additional end plates 7. The first joint 15 and the second joint 16 are respectively threadedly connected to the two ends of the threaded outer rod 17. By rotating the threaded outer rod 17, the relative distance between the first joint 15 and the second joint 16 can be adjusted, so that the threaded outer rod 17 can pull the first joint 15 and the second joint 16 closer to each other, so as to offset the deformation deflection of the multi-span main beam 9 and increase the structural stability.

[0045] After the threaded outer rod 17 is corrected, the threaded outer rod 17 is welded to the first joint 15 and the second joint 16, and is subjected to force together with the temporary diagonal brace 8, thereby changing the force transmission path of the original structure and reducing the internal force of the original structure rod, thereby strengthening the rigidity and bearing capacity of the structure during the construction process. After the installation of the upper structure is completed, it can be cut off together.

[0046] In this embodiment, the deflection detection device includes an annular guide rail 18, an annular slider 19, a vertical guide rail 20, a vertical slider 21, a displacement drive device 22, a test rod 35, a horizontal pin 23, a first torsion reset device 24, an angle sensor 25 and a detection seat 26. The annular guide rail 18 is fixedly connected to the shear wall 27. The other end of the annular guide rail 18 can be provided with a support, or arranged on the lower structural surface. The annular slider 19 is slidably installed on the annular guide rail 18, and the annular slider 19 can slide along the annular guide rail 18. The annular guide rail 18 is arranged in an annular shape on the lower side of the outer layer of the reinforcement layer, and is separated from the reinforcement layer by a certain distance. The test rod 35 can penetrate inward to detect the deflection of the multi-span main beam 9.

[0047] Specifically, the vertical guide rail 20 is fixed on the annular slider 19 and can move with the annular slider 19. The displacement driving device 22 can drive the vertical slider 21 to slide vertically on the vertical guide rail 20. The displacement driving device 22 includes a motor 34 and a screw connected to the output end of the motor 34. The screw is threadedly connected to the vertical slider 21. The motor 34 rotates to drive the vertical slider 21 to slide along the vertical guide rail 20. The detection seat 26 is installed on the vertical slider 21. The angle sensor 25 is installed on the detection seat 26. One end of the test rod 35 is rotatably connected to the detection seat 26 through the horizontal pin 23. The first torsion reset device 24 is connected between the test rod 35 and the detection seat 26. The other end of the test rod 35 extends outward to form a detection end. The horizontal pin 23 is connected to the input end of the angle sensor 25. When the test rod 35 detects deflection deformation on the multi-span main beam 9, the test rod 35 rotates around the horizontal pin 23. At this time, the angle sensor 25 is triggered and can be used to record the deformation.

[0048] In this embodiment, the detection seat 26 is rotatably connected to the vertical slider 21 through the vertical pin 28. When the test rod 35 moves longitudinally and contacts the cantilever column 2, it can drive the detection seat 26 to rotate around the vertical pin 28 to make way, so as to avoid affecting the contact and causing damage to the device. A second torsion reset device 29 is connected between the detection seat 26 and the vertical slider 21. The second torsion reset device 29 uses a coil spring, and its two ends are respectively connected to the detection seat 26 and the vertical slider 21. By setting the second torsion reset device 29, the detection seat 26 can be restored to its original position after rotating.

[0049] In this embodiment, the annular guide rail 18 is detachably connected to the shear wall 27 through the bottom plate 30, and the position of the annular guide rail 18 is adjusted to keep it horizontal. The bottom plate 30 is equipped with a driving wheel 31 and a tensioning wheel 32 for simultaneous rotation. A belt 33 is installed between the driving wheel 31 and the tensioning wheel 32. The annular slider 19 is fixedly connected to the belt 33. The driving wheel 31 is connected to a motor 34, and the motor 34 is installed on the shear wall 27. In the above manner, the annular slider 19 can be rotated around the annular guide rail 18, and the deflection deformation of multiple positions at the bottom of the multi-span main beam 9 can be detected, which is more convenient.

[0050] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A temporary diagonal brace reinforcement method suitable for cantilever steel frames, characterized in that: The following steps are involved: Step 1: hoist the fixed-end main beam and the cantilever column of the reinforcement layer respectively and weld them, hoist multiple groups of fixed-end main beams in parallel, weld one end of the fixed-end main beam to the fixed-end bracket on the shear wall through the fixed-end weld, keep the cantilever column and the fixed-end main beam vertical, and weld the other end of the fixed-end main beam to the beam-column node bracket installed on one side of the cantilever column through the node bracket weld; Step 2: Weld the end plates at the shear wall node position and the cantilever column node position respectively, and weld the two ends of the temporary diagonal brace to the end plates at the two node positions respectively; Step 3: The multi-span parts are constructed in the same way as the above steps. The multi-span main beams and the cantilever columns connected thereto are hoisted. The multi-span main beams and the beam-column node brackets are welded with node bracket welds. Then, the end plates and temporary diagonal braces of the corresponding spans are welded. The multi-frame frames are connected with connecting beams to form a truss system in the reinforcement layer. Step 4: After the reinforcement layer structure is installed, the upper structure is installed on the upper side of the reinforcement layer; Step 5: After the superstructure is installed, all the end plates of the reinforcement layer are cut off and removed together with the temporary diagonal braces. The reinforcement layer is transformed from a truss system to a frame system, reaching the designed state; Step 4: During the construction process, first hoist the upper cantilever column in the non-reinforced layer, and connect the upper cantilever column with the cantilever column of the reinforced layer by butt welding. Then hoist the upper main beam, and weld the two ends of the upper main beam to the reserved bracket of the upper cantilever column or the bracket of the fixed support end on the shear wall. Use connecting beams to connect multiple frames. In step 4, when installing the upper structure, a stress detection device is installed on the temporary diagonal brace. The stress detection device is used to detect the internal force of the temporary diagonal brace. When the internal force monitored during the construction process exceeds the safety warning value, the construction organization is adjusted to reduce the number of floor construction personnel and equipment, and the temporary diagonal brace is installed for reinforcement; In step 4, when installing the upper structure, a deflection detection device is installed, and the deformation deflection of the multi-span main beams is detected by the deflection detection device at the same time. When the deflection is detected to exceed the preset deflection threshold, an additional end plate is welded at the shear wall node position and the cantilever column node position, and a first joint and a second joint are respectively installed on the two additional end plates. The first joint and the second joint are respectively threadedly connected to the two ends of the threaded outer rod, and the relative distance between the first joint and the second joint can be adjusted by rotating the threaded outer rod; The deflection detection equipment includes an annular guide rail, an annular slider, a vertical guide rail, a vertical slider, a displacement drive device, a test rod, a horizontal pin shaft, a first torsion reset device, an angle sensor and a detection seat. The annular guide rail is fixedly connected to the shear wall, the annular slider is slidably installed on the annular guide rail, the vertical guide rail is fixed on the annular slider, the displacement drive device can drive the vertical slider to slide vertically on the vertical guide rail, the detection seat is installed on the vertical slider, the detection seat is installed with an angle sensor, one end of the test rod is rotatably connected to the detection seat through a horizontal pin shaft, the first torsion reset device is simultaneously connected between the test rod and the detection seat, the other end of the test rod extends outward to form a detection end, and the horizontal pin shaft is connected to the input end of the angle sensor.

2. A temporary diagonal brace reinforcement method for cantilever steel frames according to claim 1, characterized in that: The detection seat is rotatably connected to the vertical slider via a vertical pin shaft, and a second torsion reset device is simultaneously connected between the detection seat and the vertical slider.

3. A temporary diagonal brace reinforcement method suitable for cantilever steel frames according to claim 1 or 2, characterized in that: The annular guide rail is detachably connected to the shear wall through the base plate. The position of the annular guide rail is adjusted to keep it horizontal. A driving wheel and a tensioning wheel are rotated simultaneously on the base plate. A belt is installed between the driving wheel and the tensioning wheel. The annular slider is fixedly connected to the belt. The driving wheel is connected to a motor, and the motor is installed on the shear wall.

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