Structural Steel Brand Inspection
Content of Inspection:
1. First, confirm and verify the facility type: Roof trusses, steel structural wall signs, and column grid structures.
2. There are two situations present in the on-site work:
Field surveying without blueprints
Panel frame dimensions, component models, rivet (bolt) spacing; rear structural frame dimensions, component models, connections; panel frame to structural system, connections between structure and ground/roof/wall; sketch of frame with specific dimensions and clear model identification.
b. Verify on-site when drawings are available:
Differentiate between primary and secondary load-bearing components, verify the models of all primary components, align the actual structure with the drawings, and conduct random inspections of secondary components. Document any structural or rod discrepancies from the drawings.
3. Load Capacity Verification
The forces exerted on outdoor signs can be categorized into permanent and variable forces. Permanent forces include the structural self-weight, the weight of the sign or fixed equipment (such as lighting facilities), the weight of the operational platform, the soil weight and pressure of ground-mounted signs, and ground deformation. Variable loads encompass wind loads, icing loads, snow loads, installation and maintenance loads, frequent seismic actions, and temperature variations. In the inspection of signs, primary consideration is given to wind loads and structural self-weight. Utilizing SAP2000, structural model analysis is conducted based on on-site inspection data, taking into account the importance factors of structural components, basic wind pressure, seismic intensity, and load combinations considered. Based on the analysis results, corrective measures are determined.
4. Key issues identified through inspection and analysis: a. Structural system; b. Connections; c. Corrosion resistance; d. Lightning protection; e. Circuitry.

Key points to note when inspecting and certifying steel structure interlayers include:
1. Basic information on the main structure and the inserted layer. The main structure serves as the load-bearing component for the inserted layer, and a highly redundant main structure ensures the safety of the inserted layer. Key aspects of the inserted layer include its later use, load, connection with the main structure, and primary column spacing and span, all of which significantly impact the handling of the inserted layer structure.
2. The materials and structural forms used in the interlayer. Generally, the combination of steel structures and corrugated steel plates is employed. However, due to the complexity of the actual conditions, materials may vary. The structural form is typically a frame structure, which may also include suspended columns. Additionally, the presence of existing interlayers on-site and the construction of new ones next to them can lead to uncertainties regarding the connection between the old and new interlayers.
3. Key practices for interlayer construction and inspection of various nodes. The connection nodes between the interlayer and the main structure are crucial; this is one of the points to consider. Ensuring a secure connection with the main structure and that it has sufficient stiffness to provide a robust load-bearing system for the interlayer. The column foot nodes of the interlayer's steel columns are also significant. Next, inspect the internal structure of the interlayer, typically checking the welding condition of seams or the bolted connections.
4. Conduct qualitative analysis on the interlayer structure and related nodes, with necessary computational analysis. Provide conclusions on the normal operation of the interlayer, and simultaneously analyze any points of non-standardization or potential safety hazards.