Why is bearing condition monitoring important during NBIS?

• A. Bearing wear or damage alters load transfer and can lead to misalignment or failure if not addressed.
• B. Bearing condition has no impact on load transfer.
• C. Bearing wear only affects color.
• D. Bearing condition is relevant only for aesthetics.

Answer: (A)

Bearing condition monitoring is essential because bearings are the interface that transfers loads from the bridge structure to the supports while allowing necessary movement. When a bearing wears or is damaged, its stiffness and load path change, which can cause misalignment of girders and uneven load distribution. That misalignment raises stresses in members, increases the risk of further damage or fatigue, and can lead to premature bearing or deck component failure if not addressed. Detecting wear or damage early allows maintenance to restore proper alignment and load transfer, preventing larger safety or service-life problems.

The other options don’t fit because bearing condition directly affects how loads are carried and how the structure behaves; it’s not about color or aesthetics, and it’s not irrelevant to load transfer.