What does the combination of piles, footings, and caps form in a bridge?

The combination of piles, footings, and caps forms the substructure of a bridge. The substructure is crucial because it transfers the loads from the bridge superstructure to the foundation soil below. Piles are driven into the ground to reach stable soil or rock, footings distribute the weight of the bridge to a wider area, and caps provide a flat surface to support the superstructure components like girders or beams.

Understanding the function of the substructure is key in bridge design and construction. It supports the entire bridge and helps ensure its stability and durability over time. The superstructure, on the other hand, consists of the components that carry the load of traffic and connect various parts of the bridge. The deck is the surface that vehicles or pedestrians travel across, while approach refers to the road leading to the bridge. These elements, while important, do not encompass the foundational roles that piles, footings, and caps play.