What are common types of bridge bearings?

• A. Elastomeric bearings and pot bearings.
• B. Elastomeric bearings and roller bearings.
• C. Hydraulic supports and tie rods.
• D. Ball joints and rocker arms.

Answer: (A)

Bearings are the interfaces that carry vertical loads while letting the bridge move with temperature changes, loads, and rotations. The two most common types you’ll encounter are elastomeric bearings and pot bearings. Elastomeric bearings are built from layered rubber with steel end plates, making them simple, economical, and well-suited for many medium-to-short spans. They accommodate vertical loads and provide some horizontal movement and rotation. Pot bearings are hydraulic devices housed in a steel pot; they transfer load through pistons and oil, and they allow larger rotations and movements, which is advantageous for longer spans or structures in seismic zones. Roller bearings do appear in some designs, but they’re not as universally common as these two. The other options describe components not used as standard bridge bearings, such as automotive-type ball joints/rocker arms.