Steel structure engineering construction process and safety management precautions part 1

 

Preparation and Personnel Management Before Construction

1. Organize technical personnel to prepare the construction organization design for steel structure installation.

2. Develop labor deployment plans and matching plans for construction machinery before construction.

3. Plan for material entry, ensuring smooth traffic.

4. Arrange temporary facilities.

5. Ensure a smooth handover with the civil construction team, actively cooperate, and communicate effectively. Swift scheduling and efficient workforce. The construction department should establish an information database for outsourced steel structure construction teams, collecting contact information for individuals involved in steel structure production and installation, especially information about skilled technicians, for temporary scheduling and urgent operations.

6. Promote harmonious relationships and civilized construction. Strictly prohibit causing trouble or disturbances. Issues should be coordinated by the team leader, eliminating any behavior that is detrimental to unity or damages personal and company image. Otherwise, a minimum deduction of $50 per person will be applied.

7. Adhere to laws and regulations, be model citizens. Employees should enhance their own cultivation, improve their qualities, adhere to company regulations, and avoid any illegal or disciplinary actions.

8. Care for company property, follow standardized operating procedures. The use of tools and equipment should be standardized. Anyone causing damage through unauthorized actions must compensate accordingly. Deliberate damage will result in full compensation and a minimum deduction of $100 or termination.

Tools and equipment must be properly stored. Anyone losing tools and equipment due to poor management must compensate accordingly.

Compensation for wasted or lost materials will be based on the market value. Theft and resale of materials will result in compensation for losses and a minimum deduction of $500, with severe cases facing legal consequences.

9. Be cautious in speech and actions, firmly uphold the company's image and interests. Employees are prohibited from disclosing company secrets, technical information, market information, and price information to others. Any violation will result in serious penalties, including termination.

10. Emphasize learning, master the operation techniques of each process and job type, improve efficiency, and enhance craftsmanship. Engage in company-organized training actively. Employees should quickly grasp the characteristics, structures, processes, and techniques of steel structure construction and engineering. Those who do not pass training are prohibited from critical operation procedures.

11. Prioritize safety, ensure quality, and meet deadlines. Manage construction strictly according to safety requirements, leaving no room for safety violations. Maintain high quality while reasonably scheduling and completing tasks on time.

12. Implement cost-saving measures and reduce expenses. Manage materials effectively, use them reasonably, and report any design issues promptly for modification. Avoid wasting materials, losing materials, theft, and material giveaways.

Construction Layout

Construction measurement and layout should be carried out when conditions allow.

1. According to design requirements, coordinate with the civil construction unit to accurately check elevations and axis lines.

2. Before construction, use a theodolite or level to recheck axis lines and elevations. Mark them with a pen or ink line, indicating elevations and keeping records.

3. Determine the connecting surface boundary lines and axis lines for each steel column on the foundation concrete.

4. Avoid collisions between steel columns and bolts, preventing deformations at the column base. Minimize contact surface and bolt bending to reduce unnecessary losses.

5. Ensure accurate and error-free layout, with a solid and precise foundation. Any errors leading to material waste or rework will result in the responsible person bearing full responsibility, with a minimum deduction of $200.

During the layout process, pay attention to errors. Use meridian lines as much as possible during layout. In windy conditions, avoid layout to prevent errors. Due to variations in construction levels, there will be errors in each layout. To minimize errors, start with layout on both sides of the retaining walls, then use a steel ruler for measurement. If there is a discrepancy between the retaining wall line and the drawings, it indicates a deviation between the physical structure and the drawings. In such cases, corrections should be made promptly, reducing the error to a minimum, ideally within 2mm.

Foundation Embedment

1. Before pouring foundation concrete, carefully check the size, length, elevation, and position of bolts, and secure embedded bolts.

2. Wrap the bolt threads with plastic film before pouring concrete to avoid contamination during concrete pouring and tamping.

3. Assign professionals to be on duty during concrete pouring to manage the impact on bolt positioning. After concrete pouring, promptly clean residual concrete from bolts and threads.

Material Processing and Fabrication

1. Cutting Diagram

A. The cutting process involves material inspection, mainly checking the quality of the selected models, specifications, and materials for the project.

B. Quality inspection standards should comply with design requirements and current national standards.

C. Inspection methods for cutting: Check the steel quality certificate and retest report, use a steel tape measure and calipers to check models and specifications.

2. Template Layout

A. Clearly mark assembly labels, hole marks, strengthen plate positions, inclined marking lines, and centerlines during template layout. Prepare templates if necessary.

B. Pay attention to allowances for fabrication, welding shrinkage during installation, cutting margins, and installation dimensional requirements.

C. Correct material bending and deformations before marking.

D. Permissible deviations for layout and templates: 0.5mm for equal line distances and segmented dimensions, 1.0mm for diagonal differences, 0.5mm for width and length, 0.5mm for hole distances, and 20 degrees for template angles.

E. Quality inspection method using a steel ruler.

3. Cutting

For steel plate cutting, use CNC multi-head cutting machines whenever possible. Use regular cutting machines or oxy-acetylene cutting if necessary. Before cutting, remove rust and dirt from the cutting surface to keep cut pieces clean and flat. After cutting, remove slag and splatters. Operators should be proficient in machinery operation, understand equipment usage, and follow operating procedures to adjust equipment to optimal parameters.

A. Quality inspection standards for cutting allow a deviation of 2mm.

B. Steel shear or cutting surfaces should be free of cracks, slag inclusions, and delamination.

C. Quality inspection method: visual inspection or check with a steel ruler.

4. Welding

Use automatic submerged arc welding for welding steel columns and beams. Manual welding is used for welding column-beam connection plates and rib plates. The following two points must be satisfied for automatic welding:

A. Clean rust, burrs, and dirt within 30mm-50mm of the welding edge after welding to reduce the factors causing welding defects.

B. The starting plate should be of the same material as the base material, with the same welding groove form. The length should meet the standard requirements. For manual arc welding, the following requirements must be met:

Use a well-functioning electric welding machine and use a drying machine to dry the welding rods.

5. Rust Removal

Use specialized rust removal equipment for shot blasting to improve the fatigue strength and corrosion resistance of steel. After rust removal, clean the steel surface with tools such as brushes before proceeding to the next process. Only after qualifying rust removal can the next step be carried out.

6. Painting

After rust removal inspection, apply the first coat of paint on the surface. Paint should be used according to design requirements. After the first primer is dry, apply the intermediate and topcoats. Ensure that the coating thickness meets design requirements. During the painting process, apply the paint evenly without drips.

7. Acceptance

Before steel leaves the factory, the following documents must be submitted:

A. Product qualification certificate

B.Design drawings and documents;

C. Agreements on technical issue resolutions during the production process;

D. Quality certificates and test reports for steel, connecting materials, and paint;

E. Welding seam inspection record data;

F. Paint inspection data;

G. Records of major component transportation;

H. Component shipping list data.

Construction acceptance should follow quality standards:

- "Code for Acceptance of Construction Quality of Steel Structures" GB50205-2001

- "Unified Standard for Acceptance of Construction Quality of Building Engineering" GB50300-2001

- "Technical Regulations for Portal Frame Light Steel Structures" CECS-102:2002

- "Welding Specification for Steel Structures" JGJ81-91

- "Design, Construction, and Acceptance Specification for High-Strength Bolted Connections in Steel Structures" JGJ82-91