In civil engineering, theoretical bases underpin various principles, methodologies, and design practices. These encompass structural mechanics, materials science, fluid dynamics, and geotechnical engineering. Understanding Newtonian physics, Euler$-$Bernoulli beam theory, Mohr$-$Coulomb criterion, and Reynolds number conceptually grounds civil engineering analyses. Theoretical frameworks inform structural stability, load$-$bearing capacity, and material behavior predictions. Furthermore, knowledge of differential equations, matrix algebra, and statistical methods facilitates modeling and simulation in civil engineering applications, ensuring the safety and efficiency of infrastructure projects.