Construction method for 7-shaped cantilever pipe truss installation

Abstract

The application discloses a construction method for 7-shaped cantilever pipe truss installation, comprising the following steps: S1. overall modeling of the truss structure, and reverse deformation amount is made to control overall deformation; S2. an operation platform is erected before truss installation, finished product support and centering structure are installed; S3. the truss is assembled and welded on the bottom surface, and truss hoisting auxiliary devices and a crawling ladder are installed on the truss; S4. the truss is hoisted and the truss hoisting state is adjusted to the installation state; S5. the truss is transported to the installation node and the welding of the truss and the finished product support is completed; S6. the hoisting device is unhooked and the excess hoisting auxiliary devices are removed from the truss. The construction method for 7-shaped cantilever pipe truss installation can be quickly aligned, installed in place at one time, reduces high-altitude operation time, saves construction period, reduces safety risks, avoids high-altitude segmented welding through overall assembly, reduces quality risks, realizes support-free installation through pre-stress analysis and pre-deformation measures, and reduces measure cost investment.

Description

Technical Field

[0001] The invention relates to the technical field of building construction, and in particular to a construction method for installing a 7-shaped cantilever tube truss. Background Art

[0002] A tubular truss structure is a lattice structure made of round rods connected at their ends. These trusses make the truss structure economical in material usage, lightweight, and easy to create in a variety of shapes to suit different applications, such as simply supported trusses, arches, frames, and towers.

[0003] In spatial steel structures, 7-shaped cantilever tube trusses are often used in the design of roof canopies for large outdoor stadiums or public buildings. However, the high-altitude installation of the 7-shaped truss requires workers to operate on the truss, which poses a high safety risk. Currently, there are two construction methods for the 7-shaped cantilever tube truss structure: 1. The 7-shaped cantilever tube truss structure is manufactured in two sections at the factory. The two sections are then assembled separately on the ground at the construction site and installed by connecting them at high altitude, but temporary supports are provided at the joints between the two sections. 2. When the equipment has sufficient lifting capacity and the on-site working conditions are good, the 7-shaped cantilever tube truss is assembled as a whole on the ground and then installed at high altitude in one go. Among them, the first construction method has the disadvantages of large workload of high-altitude welding, difficult quality control, prominent safety risks of high-altitude operations, and high cost of temporary facilities. It is generally used for structures with large cantilever lengths or structures that cannot be hoisted and constructed as a whole at one time due to restrictions on lifting equipment and site. The second construction method is divided into two cases: with support and without support. When there is support, it is usually necessary to set up temporary steel structure support at the cantilever end. After the construction of the roof steel structure is completed, the temporary support is removed. After the overall unloading is completed, the roof metal system is continued to be constructed. It has the disadvantages of high cost of measures and long construction period. Unsupported hoisting lacks a method for quickly locating multiple installation nodes, and also has the disadvantages of high cost of measures, long construction period, and great construction difficulty. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a construction method for the installation of a 7-shaped cantilever tube truss, which utilizes an unsupported construction method to install the 7-shaped cantilever tube truss structure in place at high altitude at one time; and by simulating the construction steps in advance, calculating and analyzing the overall stress and deformation of the structure, and taking pre-reverse deformation measures to achieve reasonable structural stress and deformation that meets the requirements of the specifications, thereby reducing the investment in temporary support costs.

[0005] The present invention provides a construction method for installing a 7-shaped cantilever tube truss, comprising the following steps:

[0006] S1. Build an overall model of the 7-shaped cantilever tube truss structure to be installed, and analyze and calculate the maximum downward deformation of the cantilever section during the construction phase. Then, during factory fabrication of the truss structure, perform the corresponding reverse deformation to control the overall deformation.

[0007] S2. Before installing the trusses, set up an operating platform near the structural columns at the installation nodes and install the finished supports. Then, install the centering structure used to align the hemispherical structure installation guide on the finished supports.

[0008] S3. Assemble and weld the trusses on a ground assembly platform according to the design drawings. After the welding quality is inspected and accepted, install the truss lifting auxiliary device and ladder on the truss.

[0009] S4. Use a lifting device to lift the truss and keep it off the ground. The operator climbs up the truss using a ladder and adjusts the truss to the installation position using the lifting auxiliary device.

[0010] S5. Use a lifting device to transport the truss to the top of the installation node and verify that the truss is in the hoisted state. Once confirmed, use the centering structure on the finished support to align the truss installation guide. Then, weld the hemispherical structure on the tube truss to the finished support.

[0011] S6. Unhook the lifting equipment and remove any unnecessary lifting auxiliary devices from the truss to complete the lifting of the single truss.

[0012] Furthermore, in step S1 , the reverse deformation of the truss structure during factory processing is half of the maximum downward deformation.

[0013] Further, in step S2, the centering structure includes an outer stop block arranged on the mounting surface of the finished product support and a guide centering assembly symmetrically arranged on the side wall of the finished product support, the guide centering assembly includes a support seat for connecting with the side wall of the finished product support, a limit block and a support plate arranged on the support seat, and a guide plate rotatably arranged on the support plate, the limit block is provided with a limit surface that can limit the rotation angle of the guide plate, and the guide plate is squeezed and rotated toward the limit block during the falling process of the hemispherical structure on the tube truss until it contacts the upper limit surface of the limit block and cooperates with the outer stop block to center the hemispherical structure on the tube truss on the mounting surface of the finished product support.

[0014] Furthermore, the distance between the rotation point of the guide plate in its length direction and the end close to the hemispherical structure on the tube truss is smaller than the distance between the rotation point and the end away from the hemispherical structure on the tube truss.

[0015] Furthermore, it also includes an inner stop block arranged on the mounting surface of the finished product support, and the inner stop block is used to limit the flipping of the guide plate in the free state.

[0016] Furthermore, it also includes a pushing assembly for moving the hemispherical structure on the pipe truss close to the push block, and the pushing assembly is arranged on the opposite side wall of the finished product support close to the side wall of the outer stop block; the pushing assembly includes a jack and a jack support seat for installing the jack, and the jack support seat is connected and fixed to the side wall of the finished product support.

[0017] Further, in step S3, the lifting auxiliary device includes a slip rope, a safety wire rope, a lifting wire rope, a reflective sticker and a hand winch.

[0018] Furthermore, in steps S4 and S5, the operator adjusts the truss hoisting state mainly by pulling the lifting wire rope with a hand winch to adjust the truss hoisting state, and then uses a total station to align the reflective sticker to verify or check whether the truss is in the installed state.

[0019] Furthermore, in step S6, redundant lifting auxiliary devices including slip ropes, hand hoists and lifting wire ropes are removed.

[0020] The present invention has the following beneficial effects:

[0021] 1. Overall assembly, no support: Through force analysis and calculation to verify the stress and deformation of the structure under no support conditions, under the condition of safety, the overall ground welding is adopted and then the truss is hoisted into place at high altitude. There is no segmentation of the truss and no high-altitude welding.

[0022] 2. Effectively control the deformation of the truss structure: Based on the calculation and analysis of the structure, pre-deformation measures are adopted during the structural in-depth design and assembly to reduce the deformation of the truss structure.

[0023] 3. Quick installation: A quick centering device is designed at the support of the truss structure to enable the truss structure to be quickly and accurately positioned at high altitude, thus reducing high altitude installation time and lowering safety management risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0025] Figure 1 This is a schematic structural diagram of the centering structure of the present invention in a free state on a finished support;

[0026] Figure 2 This is a schematic diagram of the structure of the finished support after alignment with the hemispherical structure in the present invention;

[0027] Figure 3 This is a top view of the structure after the finished support and the hemispherical structure are aligned in the present invention;

[0028] Figure 4 This is a schematic diagram of the structure of the finished support at other angles after alignment with the hemispherical structure in the present invention;

[0029] Figure 5 This is a schematic diagram of the installation structure of the 7-shaped cantilever tube truss in the present invention;

[0030] Explanation of the accompanying reference numerals: 1-structural column; 2-finished product support; 3-hemispherical structure; 4-support seat; 5-support plate; 6-limiting block; 7-guide plate; 8-inner stopper; 9-jack support seat; 10-jack; 11-outer stopper; 12-ladder; 13-slip rope; 14-lifting wire rope; 15-safety wire rope; 16-hand hoist; 17-crane cable; 18-reflective tape; 19-operating platform. DETAILED DESCRIPTION

[0031] The present invention provides a construction method for installing a 7-shaped cantilever tube truss, comprising the following steps:

[0032] S1. Build an overall model of the 7-shaped cantilever tube truss structure to be installed. Analyze and calculate the maximum downward deformation of the cantilever segment during the construction phase. Then, during factory fabrication of the truss structure, perform a corresponding reverse deformation to control overall deformation. The reverse deformation of the truss structure during factory fabrication is half of the maximum downward deformation. For example, if the maximum downward deformation of the cantilever segment is a, then during truss fabrication, the reverse deformation should be a / 2 to achieve overall deformation control.

[0033] S2. Before the truss is installed, an operating platform 19 is set up near the structural column 1 at the installation node and the finished support 2 is installed. Then, a centering structure for installing the hemispherical structure 3 on the pipe truss is installed on the finished support 2 to guide the centering;

[0034] S3. The truss is assembled and welded on the ground assembly stand according to the design drawings, and the welding quality is inspected and accepted. Then, a truss lifting auxiliary device and a ladder 12 are installed on the truss; wherein the ladder is used to operate the worker after the truss is hoisted up, climb to the lifting point of the truss to adjust the truss hoisting status;

[0035] S4. Use lifting equipment to lift the truss and properly leave the ground. The operator climbs up the truss by the ladder 12 and adjusts the truss hoisting state to the installation state by the lifting auxiliary device;

[0036] S5. Use a lifting device to transfer the truss to the top of the installation node and verify that the truss is in the hoisted state. Once confirmed, use the centering structure on the finished support to align the truss installation guide. Then, weld the hemispherical structure 3 on the tube truss to the finished support 2.

[0037] S6. Unhook the lifting equipment and remove any unnecessary lifting auxiliary devices from the truss to complete the lifting of the single truss.

[0038] In this embodiment, in step S1, in this embodiment, in step S2, the centering structure includes an outer stopper 11 provided on the mounting surface of the finished support and a guide centering component symmetrically provided on the side wall of the finished support 2; combined Figure 1 As shown, by respectively arranging outer stop blocks 11 and guide centering components on the finished support 2 to form a three-sided guide structure, the hemispherical structure 3 on the tube truss can rely on the outer stop blocks 11 and the guide centering components to achieve rapid installation and guidance during the hoisting and falling process, and the hemispherical structure 3 can fall into the center position on the finished support 2 to complete welding and fixation, solving the problem in the prior art of lacking a device for quickly installing and positioning the finished support with the hemispherical structure at the truss installation node, and enabling the hemispherical structure on the tube truss to be quickly aligned with the finished support at the installation node and installed in place at one time, thereby reducing the time for high-altitude operations, saving construction period, and reducing safety risks.

[0039] In this embodiment, the guide centering assembly includes a support seat 4 for connecting to the side wall of the finished product support 2, a limit block 6 and a support plate 5 arranged on the support seat 4, and a guide plate 7 rotatably arranged on the support plate 5, the limit block 6 is provided with a limit surface that can limit the rotation angle of the guide plate 7, and the guide plate 7 is squeezed and rotated toward the limit block 6 during the falling process of the hemispherical structure 3 on the tube truss until it contacts the upper limit surface of the limit block 6 and cooperates with the outer stop block 11 to center the hemispherical structure 3 on the tube truss on the installation surface of the finished product support 2; combined with Figures 1 to 4 As shown, the guide plate 7 and the support plate 5 are connected by bolts so that the guide plate 7 can rotate on the support plate 5 toward the direction close to the limit block 6 when the upper hemispherical structure 3 is squeezed during the falling process; when the hemispherical structure 3 on the tube truss is installed, it gradually falls from the wider upper opening formed by the symmetrically arranged guide plates 7 and is forced to be centered along the outer baffle 11; when the hemispherical structure 3 on the tube truss falls to the lower section of the guide plate 7, the guide plate 7 rotates and abuts against the limit surface on the limit block 6, and the hemispherical structure 3 on the tube truss continues to fall along the guide plate 7 until it is stuck between the inner stop block 8 and the guide plate 7, completing the forced centering process.

[0040] In this embodiment, the distance between the rotation point of the guide plate 7 in its length direction and the end close to the hemispherical structure 3 on the tube truss is smaller than the distance between the rotation point and the end away from the hemispherical structure 3 on the tube truss; Figure 1 As shown, the guide plate 7 has a structure with a long upper section and a short lower section. Due to the unbalanced deadweight, the guide plate 7 is always in an outward tilted state in a free state, so that a larger opening is formed between the two symmetrically arranged guide plates 7 for the hemispherical structure 3 to fall into the centering structure.

[0041] In this embodiment, an inner stopper 8 is also provided on the mounting surface of the finished support, and the inner stopper 8 is used to limit the rotation of the guide plate 7 in the free state; Figure 2 and Figure 4 As shown, since the guide plate 7 has a structure with a long upper section and a short lower section and is always in an outward-inclined state in a free state, in order to prevent the guide plate 7 from rotating excessively and then leaving the mounting surface of the finished support 2 in the vertical direction, an internal stopper 8 is provided on the mounting surface of the finished support 2 to limit the maximum outward-inclined angle of the guide plate 7.

[0042] In this embodiment, it also includes a pushing component, which is arranged on the opposite side wall of the finished support 2 close to the side wall of the outer stop block 11; the pushing component includes a jack 10 and a jack support seat 9 for installing the jack 10, and the jack support seat 9 is connected and fixed to the side wall of the finished support 2; when the hemispherical structure 3 on the pipe truss falls on the mounting surface of the finished support 2 through the outer stop block 11 and the guide centering component, the hemispherical structure 3 and the finished support 2 are welded, and in order to ensure the welding strength between the hemispherical structure 3 and the finished support 2, when the hemispherical structure 3 on the pipe truss is about to fall on the mounting surface of the finished support 2, the jack 10 is used to push the hemispherical structure 3 to fit tightly with the outer stop block 1 for centering, and then before the hemispherical structure 3 and the finished support 2 are welded, the hemispherical structure 3 is clamped between the jack 10 and the outer stop block 11 to ensure the welding strength between the hemispherical structure 3 and the finished support 2.

[0043] In this embodiment, in step S3, the lifting auxiliary device includes a slip rope 13, a safety wire rope 15, a lifting wire rope 14, a reflective sticker 18 and a hand chain hoist 16; Figure 5 As shown, one end of the lifting wire rope 14 is fixed on the upper chord of the 7-shaped cantilever tube truss, and the other end is connected and fixed to the hand winch 16 which is also fixed on the upper chord of the 7-shaped cantilever tube truss. The crane cable 17 is connected to the lifting wire rope 14 for lifting. The slip rope 13 and the hand winch 16 are used to adjust the lifting status of the truss. The safety wire rope 15 is used for the operator to wear a safety belt on the truss. There are two reflective stickers 18 and they are respectively set on the lower chord of the 7-shaped cantilever tube truss and are used to cooperate with the total station to verify the lifting status of the truss.

[0044] In this embodiment, in steps S4 and S5, the operator adjusts the hoisting state of the truss mainly by pulling the lifting wire rope with a hand winch to adjust the hoisting state of the truss, and then uses the total station to align with the reflective sticker to verify or check whether the truss is in the installation state; the operator first climbs up the truss through the ladder 12, and then adjusts the hand winch 16 to keep the left and right chords of the truss in the same plane, and then the surveyor uses the total station on the ground to align with the reflective sticker 18 to measure the coordinates of the two points and calculate the H value, and compares it with the calculated value of the designed roof slope H1=Ltanα, adjusts the hand winch 16 to change the truss elevation angle so that H=H1; after the lifting equipment transfers the truss to above the installation node, the total station is used to remeasure the H value, and further adjust it if there is any change.

[0045] In this embodiment, in step S6, only the slip rope 13, the lifting wire rope 14 and the hand winch 16 need to be removed from the truss, and the other parts can be left on the truss for subsequent inspection or maintenance.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A construction method for installing a 7-shaped cantilever tube truss, characterized by: The following steps are involved: S1. Build an overall model of the 7-shaped cantilever tube truss structure to be installed, and analyze and calculate the maximum downward deformation of the cantilever section during the construction phase. Then, during factory fabrication of the truss structure, perform the corresponding reverse deformation to control the overall deformation. S2. Before installing the trusses, set up an operating platform near the structural columns at the installation nodes and install the finished supports. Then, install the centering structure used to align the hemispherical structure installation guide on the finished supports. S3. Assemble and weld the trusses on a ground assembly platform according to the design drawings. After the welding quality is inspected and accepted, install the truss lifting auxiliary device and ladder on the truss. S4. Use a lifting device to lift the truss and keep it off the ground. The operator climbs up the truss using a ladder and adjusts the truss to the installation position using the lifting auxiliary device. S5. Use a lifting device to transport the truss to the top of the installation node and verify that the truss is in the hoisted state. Once confirmed, use the centering structure on the finished support to align the truss installation guide. Then, weld the hemispherical structure on the tube truss to the finished support. S6. Unhook the lifting equipment and remove any unnecessary lifting auxiliary devices from the truss to complete the lifting of the single truss. In step S2, the centering structure includes an outer stopper provided on the mounting surface of the finished product support and a guide centering assembly symmetrically provided on the side wall of the finished product support, the guide centering assembly includes a support seat for connecting with the side wall of the finished product support, a limit block and a support plate provided on the support seat, and a guide plate rotatably provided on the support plate, the limit block is provided with a limit surface that can limit the rotation angle of the guide plate, and the guide plate is squeezed and rotated toward the limit block during the falling process of the hemispherical structure on the pipe truss until it contacts the upper limit surface of the limit block and cooperates with the outer stopper to center the hemispherical structure on the pipe truss on the mounting surface of the finished product support; The distance between the rotation point of the guide plate in its length direction and the end close to the hemispherical structure on the tube truss is smaller than the distance between the rotation point and the end away from the hemispherical structure on the tube truss; It also includes an inner stopper arranged on the mounting surface of the finished support, and the inner stopper is used to limit the flipping of the guide plate in a free state.

2. The construction method for installing a 7-shaped cantilever tube truss according to claim 1, characterized in that: In step S1 , the reverse deformation of the truss structure during factory processing is half of the maximum downward deformation.

3. The construction method for installing a 7-shaped cantilever tube truss according to claim 1, characterized in that: It also includes a pushing assembly for moving the hemispherical structure on the pipe truss close to the push block, and the pushing assembly is arranged on the opposite side wall of the finished product support close to the side wall of the outer stop block; the pushing assembly includes a jack and a jack support seat for installing the jack, and the jack support seat is connected and fixed to the side wall of the finished product support.

4. The construction method for installing a 7-shaped cantilever tube truss according to claim 1, characterized in that: In step S3, the lifting auxiliary device includes a slip rope, a safety wire rope, a lifting wire rope, a reflective tape and a hand winch.

5. The construction method for installing a 7-shaped cantilever tube truss according to claim 4, characterized in that: In steps S4 and S5, the operator adjusts the truss hoisting state mainly by pulling the lifting wire rope with a hand winch to adjust the truss hoisting state, and then uses a total station to align the reflective sticker to verify or check whether the truss is in the installed state.

6. The construction method for installing a 7-shaped cantilever tube truss according to claim 1, characterized in that: In step S6, redundant lifting auxiliary devices including slip ropes, hand hoists and lifting wire ropes are removed.

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