truss high aerial bulk method without support in lower chord and temporary pre-tension

Abstract

The present application is a kind of truss high-altitude bulk method without support in truss lower chord and carrying out temporary pre-tensioning;It includes setting tensioning measures at the bottom of truss lower chord (1.1), containing node plate (3), screw jack (2) and cross edge channel steel tension rod (4) and cross middle channel steel tension rod (5). The screw jack (2) is used to lift up and make the truss lower chord (1.1) pre-tensioned, then the truss lower chord (1.1), truss upper chord vertical web member (1.2) and truss diagonal web member (1.3) are installed in sequence to complete the high-altitude bulk of truss (1). Finally, the screw jack (2) is slowly retracted in multiple stages until the tension on the truss lower chord (1.1) is completely released to complete the tensioning and unloading of the truss (1). The method sets simple tensioning measures to pre-tension the truss lower chord, controls the stress and bending deformation of the lower chord gradually increased due to the lack of support measures during the high-altitude bulk of the truss, improves the installation accuracy of the truss and ensures the safety and reliability of the construction process.

Description

Technical Field

[0001] This invention relates to the field of steel structure construction technology, specifically a method for high-altitude assembly of trusses without supporting the lower chord and with temporary pre-tensioning. Background Technology

[0002] When installing planar trusses, it is difficult to set up temporary support frames due to poor on-site construction conditions. Furthermore, the installation of loose planar trusses at high altitudes can lead to problems such as gradually increasing deformation of the truss members and the concentration of excess stress on the lower chord members that cannot be released. This results in the truss installation accuracy not meeting the design and specification requirements and affecting structural safety. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned defects and propose a construction method for trusses to be assembled in bulk at high altitudes without the need for supporting frames, and to control the stress and deformation of the trusses.

[0004] To achieve the above objectives, the present invention is implemented as follows:

[0005] A method for high-altitude assembly of trusses without supporting the lower chord and with temporary pre-tensioning, including...

[0006] Step 1: Assemble the lower chord of the truss (1.1) on the ground and pre-camber it;

[0007] Step 2: Install welded node plate (3), jack box (2.1) and jack (2) at the bottom of the lower chord (1.1) of the truss.

[0008] Step 3: Fix the cross-side channel steel tie rod (4) and the mid-span channel steel tie rod (5) to the node plate (3) with the pin (6), and lift the screw jack (2) to fully tension the cross-side channel steel tie rod (4) and the mid-span channel steel tie rod (5) with the node plate (3) and the pin (6);

[0009] Step 4: Install the tensioned lower chord (1.1) of the truss between the steel columns (7) and weld it for fixation;

[0010] Step 5: Install the vertical web members (1.2) of the upper chord of the truss on the tensioned lower chord (1.1) and weld them for fixation;

[0011] Step 6: Install the diagonal web members (1.3) of the truss to complete the high-altitude assembly of the truss (1);

[0012] Step 7: The spiral jack (2) slowly retracts in multiple stages until the tension on the lower chord (1.1) of the truss is completely released, so as to complete the tension and unloading of the truss (1). The self-weight of the truss (1) is then borne by the lower chord (1.1), the upper chord vertical web members (1.2), and the diagonal web members (1.3).

[0013] This method addresses situations where poor construction conditions prevent the installation of temporary support measures. It provides a construction method for temporarily tensioning the lower chord of the truss to control the deformation of the truss during assembly. By setting simple tensioning measures to pre-tension the lower chord of the truss, the method controls the gradually increasing stress and bending deformation of the lower chord caused by the lack of support measures during the assembly of the truss at high altitude. This improves the installation accuracy of the truss and ensures a safe and reliable construction process. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the various components used for temporary tensioning of the lower chord of the truss in this method.

[0015] Figure 2 This is a schematic diagram of assembling the lower chord of the truss and pre-arching it in this method.

[0016] Figure 3 This is a schematic diagram showing the installation of welded node plates, jack boxes, and jacks on the lower chord of the truss in this method.

[0017] Figure 4 This diagram illustrates how, in this method, the cross-span channel steel tie rod and the mid-span channel steel tie rod are fixed to the node plate with pins, and the screw jack is used to lift them up, so that the tie rod, node plate, and pins are all tensioned.

[0018] Figure 5 This is a schematic diagram illustrating the installation of the tensioned lower chord of the truss between the steel columns in this method.

[0019] Figure 6 This is a schematic diagram illustrating the installation and welding of the upper chord vertical web members of the truss onto the tensioned lower chord of the truss in this method.

[0020] Figure 7 This diagram illustrates the process of installing the diagonal web members of the truss in this method to complete the high-altitude assembly of the truss.

[0021] Figure 8 This diagram illustrates how, in this method, the screw jack slowly retracts in multiple stages until the tension on the lower chord of the truss is completely released, thus completing the tension and unloading of the truss. The truss's self-weight is then shared by the lower chord, the upper chord, the vertical web members, and the diagonal web members.

[0022] In the diagram, 1—truss, 1.1—lower chord of the truss, 1.2—upper chord of the truss, vertical web member, 1.3—diagonal web member of the truss, 2—screw jack, 2.1—jack box, 3—node plate, 3.1—pin hole, 4—span-side channel steel tie rod, 4.1—span-side tie rod round hole, 4.2—span-side tie rod round hole stiffening plate, 4.3—span-side tie rod oblong hole, 4.4—span-side tie rod oblong hole stiffening plate, 5—mid-span channel steel tie rod, 5.1—mid-span tie rod oblong hole, 5.2—span-side tie rod oblong hole stiffening plate, 6—pin, 6.1—cotter pin, 7—steel column. Detailed Implementation

[0023] The present invention will be further illustrated below through specific embodiments.

[0024] like Figures 1 to 8 As shown, a method for high-altitude assembly of a truss without support on the lower chord and with temporary pre-tensioning includes...

[0025] Step 1: Assemble the lower chord of the truss (1.1) on the ground and pre-camber it;

[0026] Step 2: Install welded node plate (3), jack box (2.1) and jack (2) at the bottom of the lower chord (1.1) of the truss.

[0027] Step 3: The round hole (4.1) and oblong hole (4.3) of the side channel steel tie rod (4) are reinforced by welding with stiffening plates (4.2) and (4.4); the oblong hole (5.1) of the mid-span channel steel tie rod (5) is reinforced by welding with stiffening plates (5.2) and (4.4).

[0028] Connect the end of the cross-section channel steel tie rod (4) with the round hole (4.1) and the pin hole (3.1) of the node plate (3) of the lower chord (1.1) of the truss through the pin (6), and fix it by prying open the cotter pin (6.1); connect the end of the cross-section channel steel tie rod (4) with the long oval hole (4.3) and the long oval hole (5.1) of the mid-span channel steel tie rod (5) through the pin (6), and fix it by prying open the cotter pin (6.1); lift up the screw jack (2) to fully tension the cross-section channel steel tie rod (4) and the mid-span channel steel tie rod (5) with the node plate (3) and the pin (6);

[0029] The elongation of the side channel steel tie rod (4) and the middle channel steel tie rod (5) is adjusted by the gap of the elongated holes (4.3) (5.1) thereon; for this purpose, the initial fixed position of the pin (6) of the side channel steel tie rod (4) is away from the tie rod end side of the elongated hole (4.3); the initial fixed position of the pin (6) of the middle channel steel tie rod (5) is away from the tie rod end side of the elongated hole (5.1);

[0030] Step 4: Install the tensioned lower chord (1.1) of the truss between the steel columns (7) and weld it for fixation;

[0031] Step 5: Install the vertical web members (1.2) of the upper chord of the truss on the tensioned lower chord (1.1) and weld them for fixation;

[0032] Step 6: Install the diagonal web members (1.3) of the truss to complete the high-altitude assembly of the truss (1);

[0033] Step 7: The spiral jack (2) slowly retracts in multiple stages until the tension on the lower chord (1.1) of the truss is completely released, so as to complete the tension and unloading of the truss (1). The self-weight of the truss (1) is then borne by the lower chord (1.1), the upper chord vertical web members (1.2), and the diagonal web members (1.3).

[0034] This method addresses situations where poor construction conditions prevent the installation of temporary support measures. It provides a construction method for temporarily tensioning the lower chord of the truss to control the deformation of the truss during assembly. By setting simple tensioning measures to pre-tension the lower chord of the truss, the method controls the gradually increasing stress and bending deformation of the lower chord caused by the lack of support measures during the assembly of the truss at high altitude. This improves the installation accuracy of the truss and ensures a safe and reliable construction process.

Claims

1. A method for high-altitude assembly of trusses without supporting the lower chord and with temporary pre-tensioning, characterized in that: include Step 1: Assemble the lower chord of the truss (1.1) on the ground and pre-camber it; Step 2: Install welded node plate (3), jack box (2.1) and jack (2) at the bottom of the lower chord (1.1) of the truss. Step 3: Fix the cross-side channel steel tie rod (4) and the mid-span channel steel tie rod (5) to the node plate (3) with the pin (6), and lift the screw jack (2) to fully tension the cross-side channel steel tie rod (4) and the mid-span channel steel tie rod (5) with the node plate (3) and the pin (6); Step 4: Install the tensioned lower chord (1.1) of the truss between the steel columns (7) and weld it for fixation; Step 5: Install the vertical web members (1.2) of the upper chord of the truss on the tensioned lower chord (1.1) and weld them for fixation; Step 6: Install the diagonal web members (1.3) of the truss to complete the high-altitude assembly of the truss (1); Step 7: The spiral jack (2) slowly retracts in multiple stages until the tension on the lower chord (1.1) of the truss is completely released, so as to complete the tension and unloading of the truss (1). The self-weight of the truss (1) is then borne by the lower chord (1.1), the upper chord vertical web members (1.2), and the diagonal web members (1.3).

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