$2$##$143$ How do theoretical principles in civil engineering inform the design, construction, and maintenance of infrastructure? Discuss the foundational theories underlying structural analysis, materials science, and fluid mechanics, emphasizing their application in addressing engineering challenges. Explore how theoretical frameworks guide decision$-$making processes, optimize resource allocation, and ensure the safety, durability, and sustainability of civil engineering projects. Illustrate with examples the practical implications of theoretical concepts in shaping the built environment and meeting societal needs for transportation, water supply, and urban development.