Key control points for steel structure engineering supervision work

01

Qualification review of construction units

Due to the strong professionalism of steel structure engineering, there are high requirements for professional equipment, processing sites, workers' quality, as well as the construction technology standards, quality assurance system, quality control and inspection system of the enterprise itself. Generally, it is mostly subcontracted under the general contract. In this case, the qualification and management level of the construction enterprise are quite important. Therefore, qualification review is an important link, and its review content includes:

(1) Whether the construction qualification and business scale meet the engineering requirements. (2) Whether the construction technical standards, quality assurance system, quality control and inspection system meet the requirements of engineering planning technical indicators. (3) Inspect whether the production capacity of the construction enterprise meets the requirements of the project schedule.

02

Review of Welder Qualifications

Welders must pass the exam and obtain a certificate of qualification, and certified welders must perform welding on their approved projects and scales. (1) Number of views: All views (on-site personnel). (2) Inspection method: Check the welder's qualification certificate, its recognized scale, and validity period.

03

Drawing review and technical preparation

According to the drawing review procedure in the supervision plan, understand the drawings before the start of the project, convene and preside over the drawing review by professional technical personnel from the planning, owner, supervisor, and construction unit. Based on the planning documents and related materials and standards, address any errors, omissions, irrationality, non compliance with standards, and national construction documents in the construction drawings before construction. Coordinate with the owner, planning, and construction units to determine specific treatment measures or plan optimization for drawing issues. Urge the construction unit to organize the minutes of the joint review, and distribute them to all units after all parties sign and stamp them.

04

Review of construction organization planning (plan)

(1) Urge the construction unit to prepare a special construction organization plan (plan) in accordance with the construction contract. After approval by its superior unit, it shall be reported to the supervisor. (2) After review, if the construction organization plan (plan) needs to be changed during construction, the reason and content of the change must be reported to the supervisor and the construction unit for review and approval before the change can be made.

05

Regular meetings

Organize and participate in a weekly construction site meeting jointly attended by the construction, construction, and supervision units to promptly solve construction problems.

06

Key points for specific control of steel structure engineering preparation work

(1) According to the Unified Standard for Construction Quality Inspection of Building Engineering GB50300-2013 and the Standard for Construction Quality Inspection of Steel Structures GB50205-2020, as a sub project, it is divided into sub projects such as steel structure welding, fastener connection, steel parts and steel component processing, steel component assembly, steel structure pre assembly, steel structure device engineering, profiled metal plate, steel structure coating, etc Regarding the raw materials of steel structures (including steel, welding materials, coating materials, etc.), they have a significant impact on the quality of steel structures and are separately included in the steel structure standards.

(2) Check the welder qualification certificate, its recognition scale, and validity period.

(3) The construction party shall conduct welding process evaluation on the steel, welding materials, welding methods, welding heat treatment, etc. used for the first time, and determine the welding process based on the evaluation report. The supervisor has reviewed all the welding process qualification reports and reviewed them according to the planned weld quality level standards. (4) Before installing steel components, check the positioning axis (bay size and span size) and elevation of the building, as well as the standards and fastening of embedded parts, which should meet the planning requirements. (5) When the embedded steel plate on the reinforced concrete bracket top of the engineering column is directly used as the bearing surface of the steel component, the allowable error in the position of the embedded steel plate on the bearing surface should comply with the standard regulations. (6) Steel components should comply with planning requirements and the provisions of this standard. The deformation and coating detachment of steel components caused by transportation, stacking, and lifting should be corrected and modified. (7) The supporting surface of steel components should not be less than 70% of the contact surface between the top and the embedded steel plate surface, and the maximum gap at the edge should not be greater than 0.8mm. (8) Before painting, the surface of the steel should be embroidered in accordance with the planning requirements and current national standards. The treated steel surface should not have welding slag, welding scars, dust, oil stains, water, and burrs. (9) The coating, number of coating passes, and coating thickness should all meet the planning requirements, with an allowable error of -25mm. The allowable error for each layer of dry paint film thickness is -5mm. (10) The appearance of components should not be painted incorrectly or missed, and the coating should not peel or rust back. The coating should be uniform and free from obvious wrinkles, sags, pinholes, and bubbles. (11) According to the actual situation and structural form of the project, the division of inspection batches for each sub project is determined: 1) Steel structure welding sub project: for the project, each frame can be used as an inspection batch; Inspection batches can also be divided into several inspection batches based on different types of steel structure units or components combined with steel structure production and device sub items. 2) Fastener connection sub project: For the project, inspection batches can be divided based on different steel structure units and fasteners of different standards. 3) Steel parts and components processing: Steel parts and components can be divided into several inspection batches according to different types. 4) Steel component assembly: For large steel structures, the steel components produced by the factory need to be assembled into steel components as lifting units before lifting. Due to the high requirements for component assembly, several components can be used as one inspection batch based on the actual situation on site. 5) Steel structure pre assembly: For disorderly shaped steel structures, in order to ensure smooth assembly during high-altitude installation, pre assembly between relevant components needs to be carried out on the ground after production. Inspection batches can be divided according to the assembly between similar components as one inspection batch. 6) Steel structure installation: Steel structure installation can be divided into single-layer steel structure installation sub items or multi-layer and high-rise steel structure installation sub items. Single story steel structure installations can be divided into several inspection batches according to engineering zoning. Multi story and high-rise steel structure installation projects can be divided into one or several inspection batches according to the floor or construction section. 7) Molded metal plate engineering: Molded metal plate engineering includes molded metal plates used for roofs, wall panels, floor slabs, and other areas. From the material perspective, it can be divided into profiled steel plates with anti-corrosion coating on the surface, profiled aluminum plates, etc. It can be divided into one or several inspection batches based on deformation joints, floors, construction sections, or roofs, walls, floors, etc. 8) Steel structure coating engineering: The steel structure coating engineering includes anti-corrosion coating and fireproof coating. The division of inspection batches can be divided into one or several inspection batches according to the principles of steel structure production or steel structure installation engineering inspection batches. (12) The quality inspection content and corresponding qualification standards of sub projects should comply with the following provisions: 1) Steel structure welding, fastener connection, steel parts and components processing, steel component assembly, steel component pre assembly, steel structure device, profiled metal plate, steel structure coating and other sub projects should comply with the qualified quality standards; 2) Quality control materials and documents should be complete; 3) The inspection and witness testing results related to safety and function should meet the requirements of the corresponding qualified quality standards in GB50205-2020 standard;