- Preparation work
(1) Before processing the steel structure, the construction personnel shall prepare the process regulations and the chief engineer shall approve them. Carefully inspect the process preparation of each process, and prepare and mutually review the processing drawings.
(2) Inspect various materials and tools required for processing, and ensure that the process equipment meets the requirements of the process regulations.
(3) Construction personnel shall carry out technical disclosure work for each process in advance.
(4) Provide training and assessment in advance for operators on duty, confirm qualifications for special types of work, and must hold a certificate to work.
(5) Before setting out, the processing drawings should be checked and the process requirements should be mastered. Any problems found should be promptly reported to the relevant departments.
- Steel component layout
(1) During the laying out process of steel components, it is necessary to verify the quantity, material specifications, models, dimensions, etc. of the steel structure and connectors, and then carry out batching, marking and laying out, and sorting and stacking.
(2) The important node dimensions of the structure or component in the processing drawing can be sampled or calculated for verification.
(3) Before marking, the steel specifications, materials, and batch numbers must be checked, and dirt such as oil and soil on the steel surface must be removed.
- Cutting
(1) After setting out the profile steel flange plate, web plate, and end plate, use a CG1-100 semi-automatic cutting machine to cut, avoiding the phenomenon of uneven edges, missing edges, and broken corners of steel components; Rib plates and rigid support connecting plates are cut using a shearing machine; Profile shall be cut by hand or by Bench grinder.
(2) Before cutting, the surface of the steel should be cleaned of rust, oil stains, etc.
(3) Plate gas cutting should be carried out on a dedicated platform.
- Drilling
(1) The connection between steel components and connectors is connected with high-strength bolts. The position and size of the aperture require high accuracy. Use a drilling machine to drill holes.
(2) When drilling, use a drilling jig and a laminated plate sleeve drill, and fix the hole with a fixture to prevent the drilling jig or the laminated plate from being misaligned.
(3) After the drilling is completed, the burrs on the hole edge should be thoroughly removed using a polishing machine without damaging the base material.
- Assembly
(1) Before assembly, the parts should be corrected, and thicker steel plates can be corrected using a press or flame heating.
(2) The components are corrected using a flange straightening machine to correct the beams produced.
(3) The reasonable assembly sequence of components should be determined based on their structural form, welding method, and welding sequence. To reduce welding deformation.
(4) The steel columns and beams of this project are all solidly sampled on a steel platform in a 1:1 ratio, and all parts are assembled according to the processing drawings.
- Welding
(1) General requirements
Welders must hold a certificate to work.
Welding rods and fluxes should be baked according to the baking temperature specified in the technical manual before use,.
Before welding, the welder should recheck the quality of the component joint and the treatment of the welding area. If it does not meet the requirements, it should be repaired and qualified before welding can be carried out.
(2) Welding process
Before welding, the construction personnel shall prepare a welding process guide book based on the process qualification book, which specifically guides the welders to carry out welding operations.
Welding in the open air is strictly prohibited during rain or snow.
The positioning welder should have a welder qualification certificate, and the welding material used for positioning welding should be the same as the formal welding material. The positioning welding should not have defects such as pores, cracks, slag inclusions, etc.
The number of weld repairs for the same part should not exceed two.
(3) Welding of H-shaped steel
LMZ-1500 automatic gantry welding machine, automatic Submerged arc welding machine and gas shielded welding machine are used for welding all H-shaped steel members in the project to avoid defects such as missed welding, slag inclusion and weld beading.
- Inspection
(1) After the completion of component processing, the components shall be inspected and accepted in accordance with the processing drawings and relevant regulations (GB50205-2001).
(2) The acceptance standards for components are the Code for Acceptance of Construction Quality of Steel Structures (GB50205-2001) and construction drawings.
- Painting and numbering
(1) General requirements
The rust removal and coating work of a component should be carried out after the component quality inspection is qualified.
B coating flap provides professional training for coating construction personnel to familiarize themselves with the performance of relevant coatings and coating operation essentials before construction.
(2) Coating management
The variety and specifications of various coating materials should meet the design requirements.
The technical conditions of the coating used for component B must comply with professional standards and have a product qualification certificate. Coatings that have exceeded their shelf life should be retested and can only be used after passing the inspection.
- Ex-works
Pack qualified components in batches according to the lifting plan and transport them to the construction site.
- Preparation before entering the site
(1) Construction workers and relevant personnel arrive at the construction site to prepare for installation.
(2) Construction workers should provide pre entry education, comprehensively implement quality, construction period, safety and other aspects of work to the team, and have a comprehensive understanding of the difficulties and key points of all design drawings and construction plans.
(3) Conduct on-site disclosure with Party A, such as stacking sites for raw materials, components, and equipment, transportation channels, water, electricity, and accommodation, coordinate and determine construction funds and construction plans for each process, and coordinate plans for cross operation with other construction units.
(4) Review the construction process (foundation and related facilities) to ensure that the quality, elevation, central axis, geometric dimensions, parallelism, etc. of the embedded parts are correct. Complete the handover procedures.
(5) Prepare lifting machinery, equipment, tools, material plans and special tools according to the requirements of steel Structural engineering; Prepare equipment and auxiliary materials, such as cranes, welding machines, measuring instruments, manual tools, and other auxiliary equipment, and ensure vertical transportation conditions.
(6) Check and accept the positioning axis and elevation of steel components, and do a good job in setting out auxiliary lines for the installation of steel components;
(7) Responsible for the installation, transportation, lifting, positioning, calibration, tightening of bolts, welding, installation and welding of steel components;
(8) According to the actual situation on site, make appropriate adjustments and supplements to the construction operation plan and submit it to the project management department for review and approval.
source:https://zhuanlan.zhihu.com/p/76477706
