Analysis of Key Technical Points for Steel Structures in Pipe Racks
As an important component of urban underground space, the quality of steel structure design, fabrication, and installation of utility tunnels directly affects their safety, durability, and service life. The following sections will provide a detailed analysis of the technical key points for utility tunnel steel structures from three perspectives: design, fabrication, and installation.
I. Design Phase
1. Structural Selection and Layout: Based on factors such as the utility function of the pipe gallery, geological conditions, and load requirements, select an appropriate structural form—such as single-layer, multi-layer, circular, or rectangular—and carry out a rational planar and vertical layout to ensure overall structural stability and efficient space utilization.
2. Load Calculation and Analysis: Accurately calculate the long-term loads, variable loads, accidental loads, and other types of loads that the tunnel structure will bear, and perform load combination analysis to ensure the structural safety under various operating conditions.
3. Component Design and Material Selection: Based on the calculation results, design the cross-sections of each component and select appropriate steel grades and specifications to ensure that the components have sufficient strength, stiffness, and stability.
4. Node Design: The node is a critical component of the steel structure and requires detailed design to ensure clear force transmission, reasonable structural configuration, ease of construction, and compliance with seismic and fire-resistant requirements.
5. Corrosion- and Fire-Resistant Design: In response to the corrosive nature of underground environments and the associated fire risks, implement appropriate corrosion- and fire-resistant measures, such as applying anti-corrosion coatings and installing fire-retardant coatings, to extend the service life of the structure.
II. Production Phase

1. Raw Material Control: Strictly control the quality of raw materials such as steel and welding materials to ensure they meet design requirements and relevant standards and specifications.
2. Material Cutting and Processing: Advanced CNC cutting equipment and processing techniques are employed to ensure dimensional accuracy and high-quality machining of components.
3. Welding Process: Develop a reasonable welding procedure, strictly control welding parameters to ensure welding quality, and conduct necessary welding inspections, such as visual inspection and non-destructive testing.
4. Anti-corrosion Treatment: Perform anti-corrosion treatment on components strictly according to design requirements, ensuring adequate coating thickness, adhesion, and durability.
5. Pre-assembly and Acceptance: Before leaving the factory, perform pre-assembly of the components, check their dimensional accuracy and connection quality, and carry out acceptance testing to ensure that the component quality meets the design requirements.

III. Installation Phase

1. Foundation Construction: Ensure the quality of foundation construction to provide reliable support for steel structure installation.
2. Component Transportation and Lifting: Develop a reasonable transportation and lifting plan to ensure that components remain undamaged during transportation and lifting.
3. Installation Accuracy Control: Employ advanced measuring instruments and installation techniques to strictly control the installation accuracy of structural components, ensuring that the overall geometric dimensions and positions of the structure meet the design requirements.
4. Connection and Fastening: Strictly follow the design requirements for connecting and fastening components, ensuring reliable connections and clear force transmission.
5. Acceptance and Inspection: After installation is complete, conduct a comprehensive acceptance and inspection, including visual inspection, dimension measurement, weld inspection, and inspection of anti-corrosion and fire-retardant coatings, to ensure that the project quality meets the design requirements and relevant standards and specifications.

IV. Other Technical Points

1. BIM Technology Application: Utilizing BIM technology for 3D modeling of tunnel structure steelwork, collision detection, construction simulation, and other tasks to enhance design efficiency and construction quality.
2. Information-based Management: Establish an information-based management system for the tunnel’s steel structure project to achieve information-based management and quality control throughout the entire process—from design and fabrication to installation.
3. Safe and Civilized Construction: Strengthen safety management at the construction site, ensure the safety of construction personnel, and implement effective measures to minimize the impact of construction on the surrounding environment.

V. Conclusion

The steel structure engineering of utility tunnels is a complex systems project that requires close coordination and stringent control across all stages, including design, fabrication, and installation. Only by mastering and effectively applying the aforementioned technical key points can we ensure the quality and safety of utility tunnel steel structure projects, thereby providing a reliable foundation for the development and utilization of urban underground spaces.

Here are some additional notes:

The technical points mentioned above are for reference only; specific projects should be adjusted and refined according to actual conditions.
When designing, fabricating, and installing the steel structure of pipe galleries, strict adherence to relevant national standards, specifications, and technical codes is required.
It is recommended to select a firm with extensive experience and professional qualifications for the design, fabrication, and installation of tunnel steel structure projects.

We hope the above content has helped you better understand the technical key points of tunnel structure steel structures.