Construction method of large-span underhanging arc-shaped steel truss

Abstract

The application provides a large-span under-hanging arc-shaped steel truss construction method, which comprises the following steps: firstly, a three-dimensional model is established and construction condition simulation is performed to optimize structure design; then, an adjustable arc-shaped assembling jig frame is erected on the ground, arc-shaped main steel truss assembling is completed on the arc-shaped assembling jig frame, a boom, a conversion beam and an under-hanging structure are installed to form an integrated whole lifting unit; then, a hydraulic synchronous lifting system is installed on the top of a bearing steel column to perform graded lifting and monitoring, and is fixed and installed after lifting in place; finally, graded unloading and structure monitoring are performed, and subsequent structure construction and completion acceptance are performed. The application adopts ground arc-shaped jig frame whole assembling, and the arc-shaped truss is formed at one time, so that linear precision is high, deviation is small, large-area full scaffold is cancelled, materials are saved, space is released, multi-specialty cross operation can be realized, high-altitude operation is greatly reduced, safety risk is reduced, construction efficiency is improved, structure stress is ensured to be uniform, deformation is controllable, and construction quality is stable and reliable.

Description

Technical Field

[0001] This invention belongs to the field of building construction technology, and in particular relates to a construction method for a large-span, under-hanging, arc-shaped steel truss. Background Technology

[0002] In modern large public buildings, in order to meet the needs of large spaces and column-free use, large-span curved steel trusses are often used as the main load-bearing structure of the roof, and the lower ceiling, equipment pipelines and floor structure are suspended by hangers to form a suspended steel structure system.

[0003] Traditional construction methods often employ high-altitude assembly, full-span scaffolding support, and component hoisting into place piece by piece. These methods have significant drawbacks: controlling the alignment of curved trusses is difficult, and high-altitude assembly can easily lead to curvature deviations; full-span scaffolding consumes a large amount of materials and occupies a large space, making it impossible to achieve cross-disciplinary operations; high-altitude welding and installation work involves a large amount of work, resulting in high safety risks and low construction efficiency; uneven stress on the truss during lifting can easily lead to problems such as excessive deflection and localized stress concentration, making it difficult to meet the requirements of high-precision, high-efficiency, and high-safety construction. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a construction method for large-span suspended arc-shaped steel trusses. Through an integrated construction process that combines BIM-based detailed design, ground assembly, computer-controlled hydraulic synchronous lifting, and full-process monitoring and control, the method achieves precise and controllable arc-shaped truss alignment, safe and efficient construction, and uniform and stable structural stress, effectively solving the technical problems existing in traditional construction methods.

[0005] The present invention achieves the above-mentioned technical objectives through the following technical means.

[0006] A construction method for a large-span, under-hanging, curved steel truss includes the following steps:

[0007] Step 1: BIM detailed modeling and construction condition simulation;

[0008] Step 2: Assemble the curved main steel truss, hangers, transfer beams, and lower structure on the ground to form an integrated lifting unit;

[0009] Step 3: Install a hydraulic synchronous lifting system at the top of the load-bearing steel column;

[0010] Step 4: Graded lifting of the integrated lifting unit assembled in Step 2 and precise aerial positioning;

[0011] Step 5: Structural monitoring and graded unloading;

[0012] Step 6: Subsequent construction and final acceptance.

[0013] Further, step 1 includes: establishing BIM models of the arc-shaped main steel truss, hangers, transfer beams, and lower structures; simulating the stress and deformation throughout the construction process; optimizing the arc shape; and arranging lifting points. The arc-shaped main steel truss has a span of 30–45m, an arc radius of 40–70m, and a pre-camber value of L / 800–L / 1000. The arc-shaped main steel truss uses Q355B steel. The hangers use precision-rolled threaded steel with a diameter of 40–60 mm.

[0014] Furthermore, in step 2, an adjustable arc-shaped assembly frame is first erected on the ground in the projection area below the truss, and the alignment is finely adjusted according to the design arc and pre-camber value, with the accuracy controlled within ±2mm; then the arc-shaped main steel truss is assembled on the arc-shaped assembly frame, and then the hangers, transfer beams and lower structures are installed to form an integrated lifting unit, with an arc alignment deviation ≤3mm.

[0015] Further, step 3 includes: installing a lifting bracket on the top of the steel column, arranging a computer-controlled hydraulic lifting device on the lifting bracket, with a single unit lifting force of 200-600kN; using 15.20mm diameter, 1860MPa steel strand as the lifting sling, with a safety factor ≥5.0; and finally completing the no-load debugging and synchronous calibration of the lifting system.

[0016] Further, step 4 includes: lifting the integrated lifting unit assembled in step 2 according to the design load stages of 20%, 40%, 60%, 80%, and 100%, suspending it for 15 to 30 minutes at each stage and monitoring the structural status; lifting speed ≤ 5 m / h, lifting synchronization error ≤ 5 mm; fine-tuning the alignment after lifting to the design elevation, and then completing the fixed connection between the support and the steel column.

[0017] Furthermore, in step 5, the deformation of the arc-shaped main steel truss and the stress on the hangers are monitored in real time by stress and deflection sensors to control the maximum deflection of the arc-shaped main steel truss to be ≤L / 500 and the stress of the hangers to be ≤200MPa; the load is unloaded synchronously in stages at 10% of the total load, and the hydraulic synchronous lifting system is dismantled after no abnormalities are found.

[0018] Furthermore, step 6 includes: completing the construction of the suspended ceiling, electromechanical pipelines and decorative surface layer, inspecting and accepting the truss alignment, deflection, weld quality and overall stress performance, and delivering it for use after passing the inspection.

[0019] The present invention has the following beneficial effects:

[0020] 1. The ground-based arc-shaped jig is used for overall assembly, and the arc-shaped truss is formed in one step, resulting in high linear accuracy and small deviation.

[0021] 2. Eliminating large-scale full-span scaffolding saves materials, frees up space, and enables cross-disciplinary operations.

[0022] 3. Overall improvement significantly reduces high-altitude operations, substantially lowers safety risks, and increases construction efficiency.

[0023] 4. Graded lifting + synchronous control + full-process monitoring ensure uniform stress on the structure, controllable deformation, and stable and reliable construction quality. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the ground assembly of the arc-shaped main steel truss described in this invention;

[0025] Figure 2 This is a schematic diagram of the integrated lifting unit described in this invention.

[0026] Figure 3 This is a schematic diagram of the installation of the arc-shaped main steel truss described in this invention;

[0027] In the diagram: 1-Steel column; 2-Arched main steel truss; 3-Hanging rod; 4-Transfer beam; 5-Lower structure; 6-Arched assembly frame; 7-Lifting support; 8-Hydraulic lifter; 9-Steel strand; Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0029] The construction method for large-span suspended arc-shaped steel trusses according to the present invention includes the following process:

[0030] Step 1: BIM detailed modeling and construction condition simulation;

[0031] A three-dimensional model of the arc-shaped main steel truss 2, the hanger 3, the transfer beam 4, and the lower structure 5 was established. The arc shape was optimized, the lifting points were arranged, and the stress and deformation simulation of the entire construction process was carried out. The arc-shaped main steel truss 2 has a span of 30-45m, an arc radius of 40-70m, and a pre-camber value of L / 800-L / 1000. The arc-shaped main steel truss 2 uses Q355B steel, the hanger 3 uses Φ40-Φ60 precision rolled threaded steel, and the first-level welds are 100% UT flawed. The prefabrication of components and the installation of embedded parts were completed.

[0032] Step 2: Erect the curved assembly frame 6 and assemble it as a whole with the ground;

[0033] like Figure 1 As shown, an adjustable arc-shaped assembly frame 6 is erected in the truss projection area, and the alignment is finely adjusted according to the design arc and pre-camber value, with the accuracy controlled within ±2mm; the arc-shaped main steel truss 2 is assembled on the arc-shaped assembly frame 6, and then the hanger 3, transfer beam 4 and lower structure 5 are installed to form an integrated lifting unit, with the arc alignment deviation ≤3mm.

[0034] Step 3: Installation and commissioning of the hydraulic synchronous lifting system;

[0035] like Figure 2 As shown, a lifting bracket 7 is installed on the top of the load-bearing steel column 1, and a computer-controlled hydraulic lifting device 8 is arranged, with a single unit lifting force of 200-600kN; 15.20mm diameter, 1860MPa steel strand 9 is used as the lifting sling, with a safety factor ≥5.0; the no-load commissioning and synchronous calibration of the lifting system are completed.

[0036] Step 4: Graded Lifting and Precise Aerial Positioning;

[0037] like Figure 3 As shown, the integrated lifting unit, assembled in step 2, is lifted according to the design load levels of 20%, 40%, 60%, 80%, and 100%. Each level is suspended for 15-30 minutes while the structural status is monitored. The lifting speed is ≤5m / h, and the lifting synchronization error is ≤5mm. After lifting to the design elevation, the alignment is finely adjusted, and the fixed connection between the support and the steel column 1 is completed.

[0038] Step 5: Structural monitoring and graded unloading;

[0039] The deformation of the arc-shaped main steel truss 2 and the stress on the hanger 3 are monitored in real time by stress and deflection sensors. The maximum deflection of the arc-shaped main steel truss 2 is controlled to be ≤L / 500 and the stress of the hanger 3 is controlled to be ≤200MPa. The lifting system is dismantled synchronously in stages according to 10% of the total load. After no abnormalities are found, the lifting system is dismantled.

[0040] Step 6: Subsequent construction and final acceptance;

[0041] Complete the construction of the suspended ceiling, electromechanical pipelines and decorative surface layer, and inspect and accept the truss alignment, deflection, weld quality and overall stress performance. After passing the inspection, it will be put into use.

[0042] The embodiments described above are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A construction method for a large-span, under-hanging, arc-shaped steel truss, characterized in that, The process includes the following: Step 1: BIM detailed modeling and construction condition simulation; Step 2: Assemble the arc-shaped main steel truss (2), the hanger (3), the transfer beam (4) and the lower structure (5) on the ground to form an integrated lifting unit; Step 3: Install a hydraulic synchronous lifting system on the top of the load-bearing steel column (1); Step 4: Graded lifting of the integrated lifting unit assembled in Step 2 and precise aerial positioning; Step 5: Structural monitoring and graded unloading; Step 6: Subsequent construction and final acceptance.

2. The construction method for a large-span, under-hanging, arc-shaped steel truss according to claim 1, characterized in that, Step 1 includes: establishing BIM models of the arc-shaped main steel truss (2), the hanger (3), the transfer beam (4) and the lower structure (5), simulating the stress and deformation of the entire construction process, optimizing the arc shape and arranging the lifting points; wherein, the arc-shaped main steel truss (2) has a span of 30-45m, an arc radius of 40-70m, and a pre-camber value of L / 800-L / 1000, and the arc-shaped main steel truss (2) is made of Q355B steel; the hanger (3) is made of precision rolled threaded steel with a diameter of 40-60 mm.

3. The construction method for a large-span, under-hanging, arc-shaped steel truss according to claim 1, characterized in that, In step 2, firstly, an adjustable arc-shaped assembly frame (6) is erected on the ground in the projection area below the truss, and the line shape is finely adjusted according to the design arc and the pre-arch value, with the accuracy controlled within ±2mm; Then, the arc-shaped main steel truss (2) is assembled on the arc-shaped assembly frame (6), and then the hanger (3), the conversion beam (4) and the lower structure (5) are installed to form an integrated lifting unit with an arc-shaped line deviation of ≤3mm.

4. The construction method for a large-span suspended arc-shaped steel truss according to claim 1, characterized in that, Step 3 includes: installing a lifting bracket (7) on the top of the steel column (1), arranging a computer-controlled hydraulic lifter (8) on the lifting bracket (7), with a single unit lifting force of 200-600kN; using 15.20mm diameter, 1860MPa steel strand (9) as the lifting sling, with a safety factor ≥5.0; and finally completing the no-load debugging and synchronous calibration of the lifting system.

5. The construction method for a large-span, under-hanging, arc-shaped steel truss according to claim 1, characterized in that, Step 4 includes: lifting the integrated lifting unit assembled in step 2 according to the load grade design of 20%, 40%, 60%, 80%, 100%, pausing for 15-30 minutes at each level and monitoring the structural status; lifting speed ≤5m / h, lifting synchronization error ≤5mm; fine-tuning the alignment after lifting to the design elevation, and then completing the fixed connection between the support and the steel column (1).

6. The construction method for a large-span suspended arc-shaped steel truss according to claim 1, characterized in that, In step 5, the deformation of the arc-shaped main steel truss (2) and the force on the hanger (3) are monitored in real time by stress and deflection sensors. The maximum deflection of the arc-shaped main steel truss (2) is controlled to be ≤L / 500 and the stress of the hanger (3) is controlled to be ≤200MPa. The hydraulic synchronous lifting system is dismantled after unloading in stages at 10% of the total load and after no abnormality is found.

7. The construction method for a large-span, under-hanging, arc-shaped steel truss according to claim 1, characterized in that, Step 6 includes: completing the construction of the suspended ceiling, electromechanical pipelines and decorative surface layer, inspecting and accepting the truss alignment, deflection, weld quality and overall stress performance, and delivering it for use after passing the inspection.

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