Which component is primarily designed to accommodate expansion and contraction due to temperature changes?

Which component is primarily designed to accommodate expansion and contraction due to temperature changes?

• A. Deck
• B. Bearing
• C. Pier
• D. Abutment

Answer: (B)

Bridges change length with temperature, so a mechanism is needed to let parts move without causing damage. Bearings are designed to do that work: they sit between the bridge deck and its supports and allow controlled sliding, rotation, and other movements. This keeps the deck from gurring into the piers or abutments as it expands or contracts, while still transferring loads safely to the supports. Piers and abutments themselves are fixed supports that resist loads, not devices meant to absorb large thermal movement, and the deck relies on bearings (often along with expansion joints) to accommodate that movement. So the component whose primary job is to handle expansion and contraction is the bearing.

Bridges change length with temperature, so a mechanism is needed to let parts move without causing damage. Bearings are designed to do that work: they sit between the bridge deck and its supports and allow controlled sliding, rotation, and other movements. This keeps the deck from gurring into the piers or abutments as it expands or contracts, while still transferring loads safely to the supports. Piers and abutments themselves are fixed supports that resist loads, not devices meant to absorb large thermal movement, and the deck relies on bearings (often along with expansion joints) to accommodate that movement. So the component whose primary job is to handle expansion and contraction is the bearing.