Consequences: The weak axis of the H-type column is not supported, resulting in overall instability (e.g., a warehouse column with a height of 10m is not equipped with a tie rod, and it tilts half a year after it was put into production)

Correct: When the calculated length of the weak axis is ≤6m, one support is provided, and when it is >6m, it is increased (spacing ≤4.5m)

Error: No diaphragm is provided inside the box-type column

Hazard: Shear buckling of the web (there was a project where the diaphragm spacing was 3m, and the column body made abnormal noises during crane operation)

Specifications: The spacing of diaphragms is ≤2 times the short side size of the section (e.g., the spacing of □800×600 columns is ≤1.2m)

Error: The weld of the bracket is not inspected

Risk: The fracture of the bracket causes a chain collapse (the weld of the bracket of a factory building is not fully melted and suddenly falls off under the load of the crane)

Requirement: 100% ultrasonic flaw detection (level 1) of the bracket weld of the crane beam, and ≥20% of other brackets Spot check

From the economical and practical H-type column to the heavy-load bearing of the box-type column, from the lightweight design of the lattice column to the precise force transmission of the corbel node, each column type and each component is the crystallization of mechanical principles and engineering practice. Beginners should remember: there is no "best" in the selection of steel columns, only "the most suitable" - choose H-type columns for light loads, box columns for heavy loads, and lattice columns for large cross-sections. The size and connection method of each component must be accurately matched with the force requirements and construction conditions.