How does the base theory in civil engineering form the foundational principles for designing and constructing infrastructure projects? What are the key elements of base theory that engineers rely on to ensure structural stability, durability, and safety in buildings, bridges, roads, and other civil works? How do factors such as soil composition, load$-$bearing capacity, and environmental conditions influence the design and implementation of base structures? In what ways do advancements in base theory contribute to innovation and sustainability in civil engineering practices?