Core Quantitative Wear Assessment Criteria
Rolling-element supports: Replacement is mandatory if the roller diameter shows wear exceeding 5% or if scratches with a depth of ≥1 mm appear on the rail surface.
Steel structure supports: Replacement is required if the steel exhibits severe material defects such as significant segregation, delamination, lamellar tearing, metallic inclusions, or interlayers.
Concrete supports: Replacement is required if the concrete shows significant loosening or pulverization, or if extensive harmful cracking is present.
Assessment of Visual and Structural Damage
Steel components: Replacement is required if they exhibit irreversible damage-such as corrosion, cracks, fractures, or unauthorized cutting-that cannot be remedied to restore structural integrity.
Concrete components: Replacement is required if there is large-scale spalling, severe rebar corrosion, or structural deformation exceeding design limits.
Compliance Testing and Special Operating Conditions
In the absence of original drawings or when there are serious doubts regarding material properties, a qualified professional agency must conduct testing and evaluation; the decision to replace is then based on the evaluation results.
Following disasters such as fires or severe earthquakes, if the support suffers irreversible loss of structural strength and fails to meet original design load requirements upon verification, replacement is required.