Which bridge component is especially critical in assessing load-bearing capacity?

Piers and abutments are essential components when assessing a bridge's load-bearing capacity because they provide the primary support necessary to transfer loads from the bridge deck down to the foundation. These components are responsible for keeping the structure stable under the weight of vehicles, pedestrians, and environmental forces such as wind and seismic activities.

The piers are vertical support structures that hold up the bridge deck and help distribute the loads vertically, while the abutments serve at the ends of the bridge, anchoring the structure and preventing lateral movement. If either of these components is compromised, the entire integrity of the bridge can be at risk, potentially leading to unsafe conditions or even failure. Monitoring their condition helps engineers ensure that the bridge can safely accommodate expected loads throughout its lifespan.

In contrast, while the bridge deck is crucial for the usability of the bridge, its primary function is to provide a surface for traffic rather than bear loads directly. Bridge approaches facilitate the transition to and from the bridge but do not play a direct role in the load-bearing dynamics of the structure. Expansion joints allow for movement due to temperature changes but do not directly affect the load capacity. Hence, understanding the condition of piers and abutments is critical for determining the overall load-bearing capacity of a