the lower portion of a structure forming the foundation that supports the superstructure of a building
The abutments, piers, or other constructions built to support the span or spans of a bridge The superstructure is supported by the substructure; the substructure is placed on the foundations
The general structure base upon which the remainder of a structure or superstructure, is supported compromising the footings and any retaining wall or other walls supported by the ground up to the ground floor level Its function is to receive the loads from the superstructure and transfer them safely down to the loadbearing foundation (More on foundations)
the abutments, piers, or other constructions built to support the span of a bridge superstructure