What is the purpose of underwater bridge inspection and how is it performed?

• A. To evaluate substructure and foundations not visible from above; performed by trained divers or ROVs with safety protocols.
• B. To inspect only the upper deck surface using standard access
• C. To measure wind loads using sensors
• D. To review construction materials only

Answer: (B)

Underwater inspection aims to check parts of a bridge that are submerged or not visible from above, such as substructures and foundations. This includes piers, piles, abutments, bearings, and areas affected by scour or concrete deterioration. The goal is to identify damage, corrosion, movement, or other conditions that could compromise the bridge’s stability, which isn’t evident from the surface.

Because these elements are below water and often out of reach, trained divers or remotely operated vehicles (ROVs) are used to perform the inspection and document findings. Safety protocols are essential: qualified personnel, proper underwater procedures, rescue readiness, and adherence to established inspection methods ensure the work is thorough and safe.

The other options don’t fit because they describe activities that aren’t about inspecting submerged structural components: focusing only on the upper deck surface misses the submerged parts; measuring wind loads with sensors deals with dynamic effects on the superstructure, not underwater conditions; and reviewing construction materials alone doesn’t address the ongoing condition of submerged elements or the potential for hidden deterioration.